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- Table of Contents
-
- 07-Layer 3—IP Services Command Reference
- 00-Preface
- 01-ARP commands
- 02-IP addressing commands
- 03-DHCP commands
- 04-DNS commands
- 05-NAT commands
- 06-IP forwarding basics commands
- 07-Fast forwarding commands
- 08-Multi-CPU packet distribution commands
- 09-Adjacency table commands
- 10-IRDP commands
- 11-IP performance optimization commands
- 12-UDP helper commands
- 13-IPv6 basics commands
- 14-DHCPv6 commands
- 15-IPv6 fast forwarding commands
- 16-Tunneling commands
- 17-GRE commands
- 18-ADVPN commands
- 19-WAAS commands
- 20-AFT commands
- 21-Lighttpd service commands
- 22-Web caching commands
- Related Documents
-
| Title | Size | Download |
|---|---|---|
| 11-IP performance optimization commands | 143.74 KB |
IP performance optimization commands
display icmp statistics
Use display icmp statistics to display ICMP statistics.
Syntax
In standalone mode:
display icmp statistics
In IRF mode:
display icmp statistics [ slot slot-number ]
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command displays ICMP statistics for all member devices. (In IRF mode.)
Usage guidelines
ICMP statistics include information about received and sent ICMP packets.
Examples
# Display ICMP statistics.
<Sysname> display icmp statistics
Input: bad formats 0 bad checksum 0
echo 175 destination unreachable 0
source quench 0 redirects 0
echo replies 201 parameter problem 0
timestamp 0 information requests 0
mask requests 0 mask replies 0
time exceeded 0 invalid type 0
router advert 0 router solicit 0
broadcast/multicast echo requests ignored 0
broadcast/multicast timestamp requests ignored 0
Output: echo 0 destination unreachable 0
source quench 0 redirects 0
echo replies 175 parameter problem 0
timestamp 0 information replies 0
mask requests 0 mask replies 0
time exceeded 0 bad address 0
packet error 1442 router advert 3
display ip statistics
Use display ip statistics to display IP packet statistics.
Syntax
In standalone mode:
display ip statistics
In IRF mode:
display ip statistics [ slot slot-number ]
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command displays IP packet statistics for all member devices. (In IRF mode.)
Usage guidelines
IP statistics include information about received and sent packets, fragments, and reassembly.
Examples
# Display IP packet statistics.
<Sysname> display ip statistics
Input: sum 7120 local 112
bad protocol 0 bad format 0
bad checksum 0 bad options 0
dropped 0
Output: forwarding 0 local 27
dropped 0 no route 2
compress fails 0
Reassembling: fragments 0 reassembled 0
dropped 0 timeouts 0
Fragment: fragmented 0 couldn't fragment 0
output frags 0
Forwarded Frags: sum 0
Table 1 Command output
|
Field |
Description |
|
Input |
Statistics about received packets: · sum—Total number of packets received. · local—Total number of packets destined for the device. · bad protocol—Total number of unknown protocol packets. · bad format—Total number of packets with incorrect format. · bad checksum—Total number of packets with incorrect checksum. · bad options—Total number of packets with incorrect option. |
|
Reassembling |
Statistics about reassembling: · fragments—Total number of fragments that need reassembling. · reassembled—Total number of packets that are reassembled. · dropped—Total number of dropped fragments that fail the reassembling. · timeouts—Total number of reassembly timeouts. |
|
Fragment |
Statistics about fragments: · fragmented—Total number of packets successfully fragmented. · couldn't fragment—Total number of packets that failed to be fragmented. · output—Total number of fragments sent. |
|
Forwarded Frags |
Statistics about forwarded fragments: sum—Total number of fragments that are directly forwarded. |
Related commands
display ip interface
reset ip statistics
display rawip
Use display rawip to display brief information about RawIP connections.
Syntax
In standalone mode:
display rawip
In IRF mode:
display rawip [ slot slot-number ]
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command displays brief information about RawIP connections for all member devices. (In IRF mode.)
Usage guidelines
Brief RawIP connection information includes local and peer addresses, protocol, and PCB.
Examples
# (In standalone mode.) Display brief information about RawIP connections.
<Sysname> display rawip
Local Addr Foreign Addr Protocol Slot PCB
0.0.0.0 0.0.0.0 103 0 0xffffffffffffffa6
0.0.0.0 0.0.0.0 103 0 0xffffffffffffffa4
0.0.0.0 0.0.0.0 103 0 0xffffffffffffffa2
0.0.0.0 0.0.0.0 17 0 0xffffffffffffffa0
# (In IRF mode.) Display brief information about RawIP connections.
<Sysname> display rawip
Local Addr Foreign Addr Protocol Slot CPU PCB
0.0.0.0 0.0.0.0 1 1 0 0x0000000000000009
0.0.0.0 0.0.0.0 1 1 0 0x0000000000000008
0.0.0.0 0.0.0.0 1 5 0 0x0000000000000002
Table 2 Command output
|
Field |
Description |
|
Local Addr |
Local IP address. |
|
Foreign Addr |
Peer IP address. |
|
Protocol |
Protocol number. |
|
PCB |
Protocol control block. |
display rawip verbose
Use display rawip verbose to display detailed information about RawIP connections.
Syntax
In standalone mode:
display rawip verbose [ pcb pcb-index ]
In IRF mode:
display rawip verbose [ slot slot-number [ pcb pcb-index ] ]
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
pcb pcb-index: Displays detailed RawIP connection information for the specified PCB. The pcb-index argument specifies the index of the PCB. The index value range is 1 to 16.
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command displays detailed information about RawIP connections for all member devices. (In IRF mode.)
Usage guidelines
The detailed information includes socket creator, state, option, type, protocol number, and the source and destination IP addresses of RawIP connections.
Examples
# (In standalone mode.) Display detailed information about RawIP connections.
<Sysname> display rawip verbose
Total RawIP socket number: 1
Connection info: src = 0.0.0.0, dst = 0.0.0.0
Creator: ping[320]
State: N/A
Options: N/A
Error: 0
Receiving buffer(cc/hiwat/lowat/drop/state): 0 / 9216 / 1 / 0 / N/A
Sending buffer(cc/hiwat/lowat/state): 0 / 9216 / 512 / N/A
Type: 3
Protocol: 1
Inpcb flags: N/A
Inpcb extflag: N/A
Inpcb vflag: INP_IPV4
TTL: 255(minimum TTL: 0)
Send VRF: 0xffff
Receive VRF: 0xffff
# (In IRF mode.) Display detailed information about RawIP connections.
<Sysname> display rawip verbose
Total RawIP socket number: 1
Connection info: src = 0.0.0.0, dst = 0.0.0.0
Location: slot 6
Creator: ping[320]
State: N/A
Options: N/A
Error: 0
Receiving buffer(cc/hiwat/lowat/drop/state): 0 / 9216 / 1 / 0 / N/A
Sending buffer(cc/hiwat/lowat/state): 0 / 9216 / 512 / N/A
Type: 3
Protocol: 1
Inpcb flags: N/A
Inpcb extflag: N/A
Inpcb vflag: INP_IPV4
TTL: 255(minimum TTL: 0)
Send VRF: 0xffff
Receive VRF: 0xffff
Table 3 Command output
|
Field |
Description |
|
Total RawIP socket number |
Total number of RawIP sockets. |
|
Connection info |
Connection information, including source IP address and destination IP address. |
|
Creator |
Name of the operation that created the socket. The number in brackets is the process number of the creator. |
|
State |
State of the socket. |
|
Options |
Socket options. |
|
Error |
Error code. |
|
Receiving buffer (cc/hiwat/lowat/drop/state) |
Displays receive buffer information in the following order: · cc—Used space. · hiwat—Maximum space. · lowat—Minimum space. · drop—Number of dropped packets. · state—Buffer state: ¡ CANTSENDMORE—Unable to send data to the peer. ¡ CANTRCVMORE—Unable to receive data from the peer. ¡ RCVATMARK—Receiving tag. ¡ N/A—None of the above states. |
|
Sending buffer (cc/hiwat/lowat/state) |
Displays send buffer information in the following order: · cc—Used space. · hiwat—Maximum space. · lowat—Minimum space. · state—Buffer state: ¡ CANTSENDMORE—Unable to send data to the peer. ¡ CANTRCVMORE—Unable to receive data from the peer. ¡ RCVATMARK—Receiving tag. ¡ N/A—None of the above states. |
|
Type |
Socket type: · 1—SOCK_STREAM. This socket uses TCP to provide reliable transmission of byte streams. · 2—SOCK_DGRAM. This socket uses UDP to provide datagram transmission. · 3—SOCK_RAW. This socket allows an application to change the next upper-layer protocol header. · N/A—None of the above types. |
|
Protocol |
Number of the protocol using the socket. |
|
Inpcb flags |
Flags in the Internet PCB: · INP_RECVOPTS—Receives IP options. · INP_RECVRETOPTS—Receives replied IP options. · INP_RECVDSTADDR—Receives destination IP address. · INP_HDRINCL—Provides the entire IP header. · INP_REUSEADDR—Reuses the IP address. · INP_REUSEPORT—Reuses the port number. · INP_ANONPORT—Port number not specified. · INP_RECVIF—Records the input interface of the packet. · INP_RECVTTL—Receives TTL of the packet. Only UDP and RawIP support this flag. · INP_DONTFRAG—Sets the Don't Fragment flag. · INP_ROUTER_ALERT—Receives packets with the router alert option. Only RawIP supports this flag. · INP_PROTOCOL_PACKET—Identifies a protocol packet. · INP_RCVVLANID—Receives the VLAN ID of the packet. Only UDP and RawIP support this flag. · INP_RCVMACADDR—Receives the MAC address of the frame. · INP_SNDBYLSPV—Sends through MPLS. · INP_RECVTOS—Receives TOS of the packet. Only UDP and RawIP support this flag. · INP_USEICMPSRC—Uses the specified IP address as the source IP address for outgoing ICMP packets. · INP_SYNCPCB—Waits until Internet PCB is synchronized. · N/A—None of the above flags. |
|
Inpcb extflag |
Extension flags in the Internet PCB: · INP_EXTRCVPVCIDX—Records the PVC index of the received packet. · INP_RCVPWID—Records the PW ID of the received packet. · INP_EXTRCVICMPERR—Receives an ICMP error packet. · INP_EXTFILTER—Filters the contents in the received packet. · N/A—None of the above flags. |
|
Inpcb vflag |
IP version flags in the Internet PCB: · INP_IPV4—IPv4 protocol. · INP_TIMEWAIT—In TIMEWAIT state. · INP_ONESBCAST—Sends broadcast packets. · INP_DROPPED—Protocol dropped flag. · INP_SOCKREF—Strong socket reference. · INP_DONTBLOCK—Do not block synchronization of the Internet PCB. · N/A—None of the above flags. |
|
TTL |
TTL value in the Internet PCB. |
|
Send VRF |
VRF from which packets are sent. |
|
Receive VRF |
VRF from which packets are received. |
display tcp
Use display tcp to display brief information about TCP connections.
Syntax
In standalone mode:
display tcp
In IRF mode:
display tcp [ slot slot-number ]
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command displays brief information about TCP connections for all member devices. (In IRF mode.)
Usage guidelines
Brief TCP connection information includes local IP address, local port number, peer IP address, peer port number, and TCP connection state.
Examples
# (In standalone mode.) Display brief information about TCP connections.
<Sysname> display tcp
*: TCP connection with authentication
Local Addr:port Foreign Addr:port State Slot PCB
0.0.0.0:21 0.0.0.0:0 LISTEN 0 0xffffffffffffffa3
0.0.0.0:23 0.0.0.0:0 LISTEN 0 0xffffffffffffff9f
0.0.0.0:53 0.0.0.0:0 LISTEN 0 0xffffffffffffffa1
0.0.0.0:80 0.0.0.0:0 LISTEN 0 0xffffffffffffffa6
0.0.0.0:443 0.0.0.0:0 LISTEN 0 0xffffffffffffffa8
0.0.0.0:6633 0.0.0.0:0 LISTEN 0 0xffffffffffffff9d
192.168.100.39:23 192.168.1.244:53986 ESTABLISHED 0 0xffffffffffffffa9
192.168.100.39:23 192.168.100.10:56055 ESTABLISHED 0 0xffffffffffffffaa
# (In IRF mode.) Display brief information about TCP connections.
<Sysname> display tcp
*: TCP MD5 Connection
Local Addr:port Foreign Addr:port State Slot CPU PCB
*0.0.0.0:21 0.0.0.0:0 LISTEN 1 0 0x000000000000c387
192.168.20.200:23 192.168.20.14:1284 ESTABLISHED 1 0 0x0000000000000009
192.168.20.200:23 192.168.20.14:1283 ESTABLISHED 1 0 0x0000000000000002
Table 4 Command output
|
Field |
Description |
|
* |
Indicates that the TCP connection uses authentication. |
|
Local Addr:port |
Local IP address and port number. |
|
Foreign Addr:port |
Peer IP address and port number. |
|
State |
TCP connection state. |
|
PCB |
PCB index. |
display tcp statistics
Use display tcp statistics to display TCP traffic statistics.
Syntax
In standalone mode:
display tcp statistics
In IRF mode:
display tcp statistics [ slot slot-number ]
Views
Predefined user roles
network-admin
network-operator
Parameters
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command displays TCP traffic statistics for all member devices. (In IRF mode.)
Usage guidelines
TCP traffic statistics include information about received and sent TCP packets and Syncache/syncookie.
Examples
# Display TCP traffic statistics.
<Sysname> display tcp statistics
Received packets:
Total: 4150
packets in sequence: 1366 (134675 bytes)
window probe packets: 0, window update packets: 0
checksum error: 0, offset error: 0, short error: 0
packets dropped for lack of memory: 0
packets dropped due to PAWS: 0
duplicate packets: 12 (36 bytes), partially duplicate packets: 0 (0 bytes)
out-of-order packets: 0 (0 bytes)
packets with data after window: 0 (0 bytes)
packets after close: 0
ACK packets: 3531 (795048 bytes)
duplicate ACK packets: 33, ACK packets for unsent data: 0
Sent packets:
Total: 4058
urgent packets: 0
control packets: 50
window probe packets: 3, window update packets: 11
data packets: 3862 (795012 bytes), data packets retransmitted: 0 (0 bytes)
ACK-only packets: 150 (52 delayed)
unnecessary packet retransmissions: 0
Syncache/syncookie related statistics:
entries added to syncache: 12
syncache entries retransmitted: 0
duplicate SYN packets: 0
reply failures: 0
successfully build new socket: 12
bucket overflows: 0
zone failures: 0
syncache entries removed due to RST: 0
syncache entries removed due to timed out: 0
ACK checked by syncache or syncookie failures: 0
syncache entries aborted: 0
syncache entries removed due to bad ACK: 0
syncache entries removed due to ICMP unreachable: 0
SYN cookies sent: 0
SYN cookies received: 0
SACK related statistics:
SACK recoveries: 1
SACK retransmitted segments: 0 (0 bytes)
SACK blocks (options) received: 0
SACK blocks (options) sent: 0
SACK scoreboard overflows: 0
Other statistics:
retransmitted timeout: 0, connections dropped in retransmitted timeout: 0
persist timeout: 0
keepalive timeout: 21, keepalive probe: 0
keepalive timeout, so connections disconnected: 0
fin_wait_2 timeout, so connections disconnected: 0
initiated connections: 29, accepted connections: 12, established connections:
23
closed connections: 50051 (dropped: 0, initiated dropped: 0)
bad connection attempt: 0
ignored RSTs in the window: 0
listen queue overflows: 0
RTT updates: 3518(attempt segment: 3537)
correct ACK header predictions: 0
correct data packet header predictions: 568
resends due to MTU discovery: 0
packets dropped due to MD5 authentication failure: 0
packets that passed MD5 authentication: 0
sent Keychain-encrypted packets: 0
packets that passed Keychain authentication: 0
packets dropped due to Keychain authentication failure: 0
packets dropped with MD5 authentication: 0
packets permitted with MD5 authentication: 0
reset tcp statistics
display tcp verbose
Use display tcp verbose to display detailed information about TCP connections.
Syntax
In standalone mode:
display tcp verbose [ pcb pcb-index ]
In IRF mode:
display tcp verbose [ slot slot-number [ pcb pcb-index ] ]
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
pcb pcb-index: Displays detailed TCP connection information for the specified PCB. The index value range is 1 to 16.
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command displays detailed information about TCP connections for all member devices. (In IRF mode.)
Usage guidelines
The detailed TCP connection information includes socket creator, state, option, type, protocol number, source IP address and port number, destination IP address and port number, and connection state.
Examples
# (In standalone mode.) Display detailed information about TCP connections.
<Sysname> display tcp verbose
TCP inpcb number: 1(tcpcb number: 1)
Connection info: Src = 192.168.20.200:179 , Dst = 192.168.20.14:4181
Location:
NSR standby: N/A
Creator: bgpd[199]
State: ISCONNECTED
Options: N/A
Error: 0
Receiving buffer(cc/hiwat/lowat/drop/state): 0 / 65700 / 1 / 0 / N/A
Sending buffer(cc/hiwat/lowat/state): 0 / 65700 / 512 / N/A
Type: 1
Protocol: 6
Inpcb flags: N/A
Inpcb extflag: N/A
Inpcb vflag: INP_IPV4
TTL: 255(minimum TTL: 0)
Connection state: ESTABLISHED
TCP options: TF_REQ_SCALE TF_REQ_TSTMP TF_SACK_PERMIT TF_NSR
NSR state: READY(M)
Send VRF: 0x0
Receive VRF: 0x0
# (In IRF mode.) Display detailed information about TCP connections.
<Sysname> display tcp verbose
TCP inpcb number: 1(tcpcb number: 1)
Connection info: Src = 192.168.20.200:179 , Dst = 192.168.20.14:4181
Location: slot 6
NSR standby: N/A
Creator: bgpd[199]
State: ISCONNECTED
Options: N/A
Error: 0
Receiving buffer(cc/hiwat/lowat/drop/state): 0 / 65700 / 1 / 0 / N/A
Sending buffer(cc/hiwat/lowat /state): 0 / 65700 / 512 / N/A
Type: 1
Protocol: 6
Inpcb flags: N/A
Inpcb extflag: N/A
Inpcb vflag: INP_IPV4
TTL: 255(minimum TTL: 0)
Connection state: ESTABLISHED
TCP options: TF_REQ_SCALE TF_REQ_TSTMP TF_SACK_PERMIT TF_NSR
NSR state: READY(M)
Send VRF: 0x0
Receive VRF: 0x0
Table 5 Command output
|
Field |
Description |
|
TCP inpcb number |
Number of TCP IP PCBs. |
|
Connection info |
Connection information, including source IP address, source port number, destination IP address, and destination port number. |
|
NSR standby |
ID of the IRF member device and number of the slot where the NSR standby card resides. This field displays N/A if no NSR standby card is present. |
|
tcpcb number |
Number of TCP PCBs. This field is not displayed if the state of the TCP connection is TIME_WAIT. |
|
Creator |
Name of the operation that created the socket. The number in brackets is the process number of the creator. |
|
State |
State of the socket. |
|
Options |
Socket options. |
|
Error |
Error code. |
|
Receiving buffer (cc/hiwat/lowat/drop/state) |
Displays receive buffer information in the following order: · cc—Used space. · hiwat—Maximum space. · lowat—Minimum space. · drop—Number of dropped packets. · state—Buffer state: ¡ CANTSENDMORE—Unable to send data to the peer. ¡ CANTRCVMORE—Unable to receive data from the peer. ¡ RCVATMARK—Receiving tag. ¡ N/A—None of the above states. |
|
Sending buffer (cc/hiwat/lowat/state) |
Displays send buffer information in the following order: · cc—Used space. · hiwat—Maximum space. · lowat—Minimum space. · state—Buffer state: ¡ CANTSENDMORE—Unable to send data to the peer. ¡ CANTRCVMORE—Unable to receive data from the peer. ¡ RCVATMARK—Receiving tag. ¡ N/A—None of the above states. |
|
Type |
Socket type: · 1—SOCK_STREAM. This socket uses TCP to provide reliable transmission of byte streams. · 2—SOCK_DGRAM. This socket uses UDP to provide datagram transmission. · 3—SOCK_RAW. This socket allows an application to change the next upper-layer protocol header. · N/A—None of the above types. |
|
Protocol |
Number of the protocol using the socket. |
|
Inpcb flags |
Flags in the Internet PCB: · INP_RECVOPTS—Receives IP options. · INP_RECVRETOPTS—Receives replied IP options. · INP_RECVDSTADDR—Receives destination IP address. · INP_HDRINCL—Provides the entire IP header. · INP_REUSEADDR—Reuses the IP address. · INP_REUSEPORT—Reuses the port number. · INP_ANONPORT—Port number not specified. · INP_RECVIF—Records the input interface of the packet. · INP_RECVTTL—Receives TTL of the packet. Only UDP and RawIP support this flag. · INP_DONTFRAG—Sets the Don't Fragment flag. · INP_ROUTER_ALERT—Receives packets with the router alert option. Only RawIP supports this flag. · INP_PROTOCOL_PACKET—Identifies a protocol packet. · INP_RCVVLANID—Receives the VLAN ID of the packet. Only UDP and RawIP support this flag. · INP_RCVMACADDR—Receives the MAC address of the frame. · INP_SNDBYLSPV—Sends through MPLS. · INP_RECVTOS—Receives TOS of the packet. Only UDP and RawIP support this flag. · INP_SYNCPCB—Waits until Internet PCB is synchronized. · N/A—None of the above flags. |
|
Inpcb extflag |
Extension flags in the Internet PCB: · INP_EXTRCVPVCIDX—Records the PVC index of the received packet. · INP_RCVPWID—Records the PW ID of the received packet. · N/A—None of the above flags. |
|
Inpcb vflag |
IP version flags in the Internet PCB: · INP_IPV4—IPv4 protocol. · INP_TIMEWAIT—In TIMEWAIT state. · INP_ONESBCAST—Sends broadcast packets. · INP_DROPPED—Protocol dropped flag. · INP_SOCKREF—Strong socket reference. · INP_DONTBLOCK—Do not block synchronization of the Internet PCB. · N/A—None of the above flags. |
|
TTL |
TTL value in the Internet PCB. |
|
TCP options |
TCP options: · TF_MD5SIG—Enables MD5 signature. · TF_PASSWORD—Password is set. · TF_NODELAY—Disables the Nagle algorithm that buffers the sent data inside the TCP. · TF_NOOPT—No TCP options. · TF_NOPUSH—Forces TCP to delay sending any TCP data until a full sized segment is buffered in the TCP buffers. · TF_BINDFOREIGNADDR—Binds the peer IP address. · TF_NSR—Enables TCP NSR. · TF_REQ_SCALE—Enables the TCP window scale option. · TF_REQ_TSTMP—Enables the time stamp option. · TF_SACK_PERMIT—Enables the TCP selective acknowledgement option. |
|
NSR state |
State of the TCP connections. Between the parentheses is the role of the connection: · M—Main connection. · S—Standby connection. |
|
Send VRF |
VRF from which packets are sent. |
|
Receive VRF |
VRF from which packets are received. |
display tcp-proxy
Use display tcp-proxy to display brief information about TCP proxy.
Syntax
In standalone mode:
display tcp-proxy
In IRF mode:
display tcp-proxy slot slot-number
The following compatibility matrix shows the support of hardware platforms for this command:
|
Hardware |
Command compatibility |
|
MSR810, MSR810-W, MSR810-W-DB, MSR810-LM, MSR810-W-LM, MSR810-10-PoE, MSR810-LM-HK, MSR810-W-LM-HK, MSR810-LMS-EA |
MSR810, MSR810-W, MSR810-W-DB, MSR810-LM, MSR810-W-LM, MSR810-10-PoE, MSR810-LM-HK, MSR810-W-LM-HK: Yes MSR810-LMS-EA: No |
|
MSR810-LMS, MSR810-LUS |
Yes |
|
MSR2600-6-X1, MSR2600-10-X1 |
Yes |
|
MSR 2630 |
Yes |
|
MSR3600-28, MSR3600-51 |
Yes |
|
MSR3600-28-SI, MSR3600-51-SI |
No |
|
MSR3600-28-X1, MSR3600-28-X1-DP, MSR3600-51-X1, MSR3600-51-X1-DP |
Yes |
|
MSR3610-I-DP, MSR3610-IE-DP |
Yes |
|
MSR3610-X1, MSR3610-X1-DP, MSR3610-X1-DC, MSR3610-X1-DP-DC |
Yes |
|
MSR 3610, MSR 3620, MSR 3620-DP, MSR 3640, MSR 3660 |
Yes |
|
MSR3610-G, MSR3620-G |
Yes |
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
slot slot-number: Specifies an IRF member device by its member ID. (In IRF mode.)
Usage guidelines
TCP proxy splits every TCP connection that passes through it into two TCP connections to relay data packets between clients and servers. The split is transparent to the servers and clients. This feature reduces bandwidth use and improves TCP performance. It is used for services such as load balancing, WAAS, and SSL VPN.
Examples
# (In standalone mode.) Display brief information about TCP proxy.
<Sysname> display tcp-proxy
Local Addr:port Foreign Addr:port State Service type
192.168.56.25:1111 111.111.111.125:8080 ESTABLISHED LB
111.111.111.125:8080 192.168.56.25:1111 ESTABLISHED LB
# (In IRF mode.) Display brief information about TCP proxy for the specified slot.
<Sysname> display tcp-proxy slot 1
Local Addr:port Foreign Addr:port State Service type
192.168.56.25:1111 111.111.111.125:8080 ESTABLISHED LB
111.111.111.125:8080 192.168.56.25:1111 ESTABLISHED LB
Table 6 Command output
|
Field |
Description |
|
Local Addr:port |
Local IP address and port number. |
|
Foreign Addr:port |
Peer IP address and port number. |
|
State |
TCP connection state. |
|
Service type |
Type of services that the TCP proxy is used for: · LB—Load balancing services. · WAAS—Wide area application services. · SSL VPN—SSL VPN services. |
display tcp-proxy port-info
Use display tcp-proxy port-info to display the usage of non-well known ports for TCP proxy.
Syntax
In standalone mode:
display tcp-proxy port-info
In IRF mode:
display tcp-proxy port-info slot slot-number
The following compatibility matrix shows the support of hardware platforms for this command:
|
Hardware |
Command compatibility |
|
MSR810, MSR810-W, MSR810-W-DB, MSR810-LM, MSR810-W-LM, MSR810-10-PoE, MSR810-LM-HK, MSR810-W-LM-HK, MSR810-LMS-EA |
MSR810, MSR810-W, MSR810-W-DB, MSR810-LM, MSR810-W-LM, MSR810-10-PoE, MSR810-LM-HK, MSR810-W-LM-HK: Yes MSR810-LMS-EA: No |
|
MSR810-LMS, MSR810-LUS |
Yes |
|
MSR2600-6-X1, MSR2600-10-X1 |
Yes |
|
MSR 2630 |
Yes |
|
MSR3600-28, MSR3600-51 |
Yes |
|
MSR3600-28-SI, MSR3600-51-SI |
No |
|
MSR3600-28-X1, MSR3600-28-X1-DP, MSR3600-51-X1, MSR3600-51-X1-DP |
Yes |
|
MSR3610-I-DP, MSR3610-IE-DP |
Yes |
|
MSR3610-X1, MSR3610-X1-DP, MSR3610-X1-DC, MSR3610-X1-DP-DC |
Yes |
|
MSR 3610, MSR 3620, MSR 3620-DP, MSR 3640, MSR 3660 |
Yes |
|
MSR3610-G, MSR3620-G |
Yes |
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command displays non-well known port usage for all member devices. (In IRF mode.)
Usage guidelines
The TCP ports are divided into well-known ports (port numbers from 0 through 1023) and non-well known ports (port numbers from 1024 through 65535).
· Well known ports are for certain services, for example, port 23 for Telnet service, ports 20 and 21 for FTP service, and port 80 for HTTP service.
· Non-well known ports are available for various services. You can use the display tcp-proxy port-info command to display the usage of these ports.
Examples
# (In standalone mode.) Display the usage of non-well known ports for TCP proxy.
<Sysname> display tcp-proxy port-info
Index Range State
16 [1024, 1087] USABLE
17 [1088, 1151] USABLE
18 [1152, 1215] USABLE
19 [1216, 1279] USABLE
20 [1280, 1343] USABLE
...
1020 [65280, 65343] USABLE
1021 [65344, 65407] USABLE
1022 [65408, 65471] USABLE
1023 [65472, 65535] USABLE
# (In IRF mode.) Display the usage of non-well known ports for TCP proxy for the specified slot.
<Sysname> display tcp-proxy port-info slot 1
Index Range State
16 [1024, 1087] USABLE
17 [1088, 1151] USABLE
18 [1152, 1215] USABLE
19 [1216, 1279] USABLE
20 [1280, 1343] USABLE
...
1020 [65280, 65343] USABLE
1021 [65344, 65407] USABLE
1022 [65408, 65471] USABLE
1023 [65472, 65535] USABLE
Table 7 Command output
|
Field |
Description |
|
Index |
Index of the port range. |
|
Range |
Start port number and end port number. |
|
State |
State of the port range: · USABLE—The ports are assignable. · ASSIGNED—Some ports are dynamically assigned and some ports are not. · ALLASSIGNED—All ports are dynamically assigned. The assigned ports can be reclaimed. · TO RECLAIM—Some ports are statically assigned. The assigned ports can be reclaimed. · RESERVED—The ports are reserved. The reserved ports cannot be dynamically assigned. |
display udp
Use display udp to display brief information about UDP connections.
Syntax
In standalone mode:
display udp
In IRF mode:
display udp [ slot slot-number ]
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command displays brief information about UDP connections for all member devices. (In IRF mode.)
Usage guidelines
Brief UDP connection information includes local IP address and port number, and peer IP address and port number.
Examples
# (In standalone mode.) Display brief information about UDP connections.
<Sysname> display udp
Local Addr:port Foreign Addr:port Slot PCB
0.0.0.0:53 0.0.0.0:0 0 0xffffffffffffffe4
0.0.0.0:67 0.0.0.0:0 0 0xffffffffffffffe3
# (In IRF mode.) Display brief information about UDP connections.
<Sysname> display udp
Local Addr:port Foreign Addr:port Slot CPU PCB
0.0.0.0:69 0.0.0.0:0 1 0 0x0000000000000003
192.168.20.200:1024 192.168.20.14:69 5 0 0x0000000000000002
Table 8 Command output
|
Field |
Description |
|
Local Addr:port |
Local IP address and port number. |
|
Foreign Addr:port |
Peer IP address and port number. |
|
PCB |
PCB index. |
display udp statistics
Use display udp statistics to display UDP traffic statistics.
Syntax
In standalone mode:
display udp statistics
In IRF mode:
display udp statistics [ slot slot-number ]
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command displays UDP traffic statistics for all member devices. (In IRF mode.)
Usage guidelines
UDP traffic statistics include information about received and sent UDP packets.
Examples
# Display UDP traffic statistics.
<Sysname> display udp statistics
Received packets:
Total: 240
checksum error: 0, no checksum: 0
shorter than header: 0, data length larger than packet: 0
no socket on port(unicast): 0
no socket on port(broadcast/multicast): 240
not delivered, input socket full: 0
Sent packets:
Total: 0
Related commands
reset udp statistics
display udp verbose
Use display udp verbose to display detailed information about UDP connections.
Syntax
In standalone mode:
display udp verbose [ pcb pcb-index ]
In IRF mode:
display udp verbose [ slot slot-number [ pcb pcb-index ] ]
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
pcb pcb-index: Displays detailed UDP connection information for the specified PCB. The value range for the pcb-index argument is 1 to 16.
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command displays detailed information about UDP connections for all member devices. (In IRF mode.)
Usage guidelines
The detailed information includes socket creator, status, option, type, protocol number, source IP address and port number, and destination IP address and port number for UDP connections.
Examples
# (In standalone mode.) Display detailed UDP connection information.
<Sysname> display udp verbose
Total UDP socket number: 1
Connection info: Src = 0.0.0.0:69, Dst = 0.0.0.0:0
Location:
Creator: sock_test_mips[250]
State: N/A
Options: N/A
Error: 0
Receiving buffer(cc/hiwat/lowat/drop/state): 0 / 41600 / 1 / 0 / N/A
Sending buffer(cc/hiwat/lowat/state): 0 / 9216 / 512 / N/A
Type: 2
Protocol: 17
Inpcb flags: N/A
Inpcb extflag: N/A
Inpcb vflag: INP_IPV4
TTL: 255(minimum TTL: 0)
Send VRF: 0xffff
Receive VRF: 0xffff
# (In IRF mode.) Display detailed UDP connection information.
<Sysname> display udp verbose
Total UDP socket number: 1
Connection info: Src = 0.0.0.0:69, Dst = 0.0.0.0:0
Location: slot 6
Creator: sock_test_mips[250]
State: N/A
Options: N/A
Error: 0
Receiving buffer(cc/hiwat/lowat/drop/state): 0 / 41600 / 1 / 0 / N/A
Sending buffer(cc/hiwat/lowat/state): 0 / 9216 / 512 / N/A
Type: 2
Protocol: 17
Inpcb flags: N/A
Inpcb extflag: N/A
Inpcb vflag: INP_IPV4
TTL: 255(minimum TTL: 0)
Send VRF: 0xffff
Receive VRF: 0xffff
Table 9 Command output
|
Field |
Description |
|
Total UDP socket number |
Total number of UDP sockets. |
|
Connection info |
Connection information, including source IP address, source port number, destination IP address, and destination port number. |
|
Creator |
Name of the operation that created the socket. The number in brackets is the process number of the creator. |
|
State |
Socket state. |
|
Options |
Socket option. |
|
Error |
Error code. |
|
Receiving buffer(cc/hiwat/lowat/drop/state) |
Displays receive buffer information in the following order: · cc—Used space. · hiwat—Maximum space. · lowat—Minimum space. · drop—Number of dropped packets. · state—Buffer state: ¡ CANTSENDMORE—Unable to send data to the peer. ¡ CANTRCVMORE—Unable to receive data from the peer. ¡ RCVATMARK—Receiving tag. ¡ N/A—None of the above states. |
|
Sending buffer(cc/hiwat/lowat/state) |
Displays send buffer information in the following order: · cc—Used space. · hiwat—Maximum space. · lowat—Minimum space. · state—Buffer state: ¡ CANTSENDMORE—Unable to send data to the peer. ¡ CANTRCVMORE—Unable to receive data from the peer. ¡ RCVATMARK—Receiving tag. ¡ N/A—None of the above states. |
|
Type |
Socket type: · 1—SOCK_STREAM. This socket uses TCP to provide reliable transmission of byte streams. · 2—SOCK_DGRAM. This socket uses UDP to provide datagram transmission. · 3—SOCK_RAW. This socket allows an application to change the next upper-layer protocol header. · N/A—None of the above types. |
|
Protocol |
Number of the protocol using the socket. |
|
Connection info |
Connection information, including source IP address, source port number, destination IP address, and destination port number. |
|
Inpcb flags |
Flags in the Internet PCB: · INP_RECVOPTS—Receives IP options. · INP_RECVRETOPTS—Receives replied IP options. · INP_RECVDSTADDR—Receives destination IP address. · INP_HDRINCL—Provides the entire IP header. · INP_REUSEADDR—Reuses the IP address. · INP_REUSEPORT—Reuses the port number. · INP_ANONPORT—Port number not specified. · INP_RECVIF—Records the input interface of the packet. · INP_RECVTTL—Receives TTL of the packet. Only UDP and RawIP support this flag. · INP_DONTFRAG—Sets the Don't Fragment flag. · INP_ROUTER_ALERT—Receives packets with the router alert option. Only RawIP supports this flag. · INP_PROTOCOL_PACKET—Identifies a protocol packet. · INP_RCVVLANID—Receives the VLAN ID of the packet. Only UDP and RawIP support this flag. · INP_RCVMACADDR—Receives the MAC address of the frame. · INP_SNDBYLSPV—Sends through MPLS. · INP_RECVTOS—Receives TOS of the packet. Only UDP and RawIP support this flag. · INP_SYNCPCB—Waits until Internet PCB is synchronized. · N/A—None of the above flags. |
|
Inpcb extflag |
Extension flags in the Internet PCB: · INP_EXTRCVPVCIDX—Records the PVC index of the received packet. · INP_RCVPWID—Records the PW ID of the received packet. · N/A—None of the above flags. |
|
Inpcb vflag |
IP version flags in the Internet PCB: · INP_IPV4—IPv4 protocol. · INP_TIMEWAIT—In TIMEWAIT state. · INP_ONESBCAST—Sends broadcast packets. · INP_DROPPED—Protocol dropped flag. · INP_SOCKREF—Strong socket reference. · INP_DONTBLOCK—Do not block synchronization of the Internet PCB. · N/A—None of the above flags. |
|
TTL |
TTL value in the Internet PCB. |
|
Send VRF |
VRF from which packets are sent. |
|
Receive VRF |
VRF from which packets are received. |
ip forward-broadcast
Use ip forward-broadcast to enable an interface to receive and forward directed broadcast packets destined for the directly connected network.
Use undo ip forward-broadcast to disable an interface from receiving and forwarding directed broadcast packets destined for the directly connected network.
Syntax
ip forward-broadcast
undo ip forward-broadcast
Default
An interface cannot forward directed broadcasts destined for the directly connected network, and can receive directed broadcasts destined for the directly connected network.
Views
Interface view
Predefined user roles
network-admin
Parameters
acl acl-number: Specifies an ACL by its number. The interface forwards only the directed broadcasts permitted by the ACL. The value range for basic ACLs is 2000 to 2999. The value range for advanced ACLs is 3000 to 3999.
Usage guidelines
A directed broadcast packet is destined for all hosts on a specific network. In the destination IP address of the directed broadcast, the network ID identifies the target network, and the host ID is made up of all ones.
If an interface is allowed to forward directed broadcasts destined for the directly connected network, hackers can exploit this vulnerability to attack the target network. In some scenarios, however, an interface must receive and send such directed broadcast packets to support UDP helper and Wake on LAN.
This command enables an interface to accept directed broadcast packets that are destined for and received from the directly connected network to support UDP helper. UDP helper converts the directed broadcasts to unicasts and forwards them to a specific server.
The command also enables the interface to forward directed broadcast packets that are destined for the directly connected network and are received from another subnet to support Wake on LAN. Wake on LAN sends the directed broadcasts to wake up the hosts on the target network.
Examples
# Enable GigabitEthernet 1/0/1 to receive and forward directed broadcast packets destined for the directly connected network.
<Sysname> system-view
[Sysname] interface gigabitethernet 1/0/1
[Sysname-GigabitEthernet1/0/1] ip forward-broadcast
ip icmp error-interval
Use ip icmp error-interval to set the interval for tokens to arrive in the bucket and the bucket size for ICMP error messages.
Use undo ip icmp error-interval to restore the default.
Syntax
ip icmp error-interval interval [ bucketsize ]
undo ip icmp error-interval
Default
A token is placed in the bucket every 100 milliseconds and the bucket allows a maximum of 10 tokens.
Views
System view
Predefined user roles
network-admin
Parameters
interval: Specifies the interval for tokens to arrive in the bucket. The value range is 0 to 2147483647 milliseconds. To disable the ICMP rate limit, set the value to 0.
bucketsize: Specifies the maximum number of tokens allowed in the bucket. The value range is 1 to 200.
Usage guidelines
This command limits the rate at which ICMP error messages are sent. Use this command to avoid sending excessive ICMP error messages within a short period that might cause network congestion. A token bucket algorithm is used with one token representing one ICMP error message.
A token is placed in the bucket at intervals until the maximum number of tokens that the bucket can hold is reached.
A token is removed from the bucket when an ICMP error message is sent. When the bucket is empty, ICMP error messages are not sent until a new token is placed in the bucket.
Examples
# Set the interval to 200 milliseconds for tokens to arrive in the bucket and set the bucket size to 40 tokens for ICMP error messages.
<Sysname> system-view
[Sysname] ip icmp error-interval 200 40
ip icmp source
Use ip icmp source to specify the source address for outgoing ICMP packets.
Use undo ip icmp source to remove the specified source address for outgoing ICMP packets.
Syntax
ip icmp source [ vpn-instance vpn-instance-name ] ip-address
undo ip icmp source [ vpn-instance vpn-instance-name ]
Default
No source address is specified for outgoing ICMP packets. The device uses the IP address of the sending interface as the source IP address for outgoing ICMP packets.
Views
System view
Predefined user roles
network-admin
Parameters
vpn-instance vpn-instance-name: Specifies an MPLS L3VPN instance to which the specified address belongs. The vpn-instance-name argument represents the VPN instance name, a case-sensitive string of 1 to 31 characters. The specified VPN instance must exist. If you do not specify a VPN instance, the ip-address argument specifies an IP address on the public network.
ip-address: Specifies an IP address.
Usage guidelines
It is a good practice to specify the IP address of the loopback interface as the source IP address for outgoing ping echo request and ICMP error messages. This feature helps users to locate the sending device easily.
Examples
# Specify 1.1.1.1 as the source address for outgoing ICMP packets.
<Sysname> system-view
[Sysname] ip icmp source 1.1.1.1
ip mtu
Use ip mtu to set the interface MTU for IPv4 packets. The MTU defines the largest size of an IPv4 packet that an interface can transmit without fragmentation.
Use undo ip mtu to restore the default.
Syntax
ip mtu mtu-size
undo ip mtu
Default
The interface MTU is not set.
Views
Interface view
Predefined user roles
network-admin
Parameters
mtu-size: Specifies the MTU in bytes. The value range for this argument is 128 to 1650.
Usage guidelines
When a packet exceeds the MTU of the sending interface, the device processes the packet in one of the following ways:
· If the packet disallows fragmentation, the device discards it.
· If the packet allows fragmentation, the device fragments it and forwards the fragments.
Fragmentation and reassembling consume system resources, so set an appropriate MTU to avoid fragmentation.
If an interface supports both the mtu and ip mtu commands, the device fragments a packet based on the MTU set by the ip mtu command.
Examples
# Set the interface MTU to 1280 bytes for GigabitEthernet 1/0/1.
<Sysname> system-view
[Sysname] interface gigabitethernet 1/0/1
[Sysname-GigabitEthernet1/0/1] ip mtu 1280
ip reassemble local enable
Use ip reassemble local enable to enable IPv4 local fragment reassembly.
Use undo ip reassemble local enable to disable local fragment reassembly.
Syntax
ip reassemble local enable
undo ip reassemble local enable
Default
IPv4 local fragment reassembly is disabled.
Views
System view
Predefined user roles
network-admin
Usage guidelines
Use this feature on a device to improve fragment reassembly efficiency. This feature enables the LPU to reassemble the IPv4 fragments of a packet if all the fragments arrive at it. If this feature is disabled, all IPv4 fragments are delivered to the active MPU for reassembly. The feature applies only to fragments received by the same LPU.
Use this feature on a multichassis IRF fabric to improve fragment reassembly efficiency. This feature enables a subordinate to reassemble the IPv4 fragments of a packet if all the fragments arrive at it. If this feature is disabled, all IPv4 fragments are delivered to the master device for reassembly. The feature applies only to fragments destined for the same subordinate.
Examples
# Enable IPv4 local fragment reassembly.
<Sysname> system-view
[Sysname] ip reassemble local enable
ip redirects enable
Use ip redirects enable to enable sending ICMP redirect messages.
Use undo ip redirects enable to disable sending ICMP redirect messages.
Syntax
ip redirects enable
undo ip redirects enable
Default
Sending ICMP redirect messages is disabled.
Views
System view
Predefined user roles
network-admin
Usage guidelines
ICMP redirect messages simplify host management and enable hosts to gradually optimize their routing tables.
A host that has only one route destined for the default gateway sends all packets to the default gateway. The default gateway sends an ICMP redirect message to inform the host of a correct next hop by following these rules:
· The receiving and sending interfaces are the same.
· The selected route is not created or modified by any ICMP redirect messages.
· The selected route is not destined for 0.0.0.0.
· There is no source route option in the received packet.
Examples
# Enable sending ICMP redirect messages.
<Sysname> system-view
[Sysname] ip redirects enable
ip ttl-expires enable
Use ip ttl-expires enable to enable sending ICMP time exceeded messages.
Use undo ip ttl-expires enable to disable sending ICMP time exceeded messages.
Syntax
ip ttl-expires enable
undo ip ttl-expires enable
Default
Sending ICMP time exceeded messages is disabled.
Views
System view
Predefined user roles
network-admin
Usage guidelines
A device sends ICMP time exceeded messages by following these rules:
· The device sends an ICMP TTL exceeded in transit message to the source when the following conditions are met:
¡ The received packet is not destined for the device.
¡ The TTL field of the packet is 1.
· When the device receives the first fragment of an IP datagram destined for the device itself, it starts a timer. If the timer expires before all the fragments of the datagram are received, the device sends an ICMP fragment reassembly time exceeded message to the source.
A device disabled from sending ICMP time exceeded messages does not send ICMP TTL exceeded in transit messages but can still send ICMP fragment reassembly time exceeded messages.
Examples
# Enable sending ICMP time exceeded messages.
<Sysname> system-view
[Sysname] ip ttl-expires enable
ip unreachables enable
Use ip unreachables enable to enable sending ICMP destination unreachable messages.
Use undo ip unreachables enable to disable sending ICMP destination unreachable messages.
Syntax
ip unreachables enable
undo ip unreachables enable
Default
Sending ICMP destination unreachable messages is disabled.
Views
System view
Predefined user roles
network-admin
Usage guidelines
A device sends ICMP destination unreachable messages by following these rules:
· The device sends the source an ICMP network unreachable message when the following conditions are met:
¡ The received packet does not match any route.
¡ No default route exists in the routing table.
· The device sends the source an ICMP protocol unreachable message when the following conditions are met:
¡ The received packet is destined for the device.
¡ The transport layer protocol of the packet is not supported by the device.
· The device sends the source an ICMP port unreachable message when the following conditions are met:
¡ The received UDP packet is destined for the device.
¡ The packet's port number does not match the running process.
· The device sends the source an ICMP source route failed message when the following conditions are met:
¡ The source uses Strict Source Routing to send packets.
¡ The intermediate device finds that the next hop specified by the source is not directly connected.
· The device sends the source an ICMP fragmentation needed and DF set message when the following conditions are met:
¡ The MTU of the sending interface is smaller than the packet.
¡ The packet has Don't Fragment set.
Examples
# Enable sending ICMP destination unreachable messages.
<Sysname> system-view
[Sysname] ip unreachables enable
reset ip statistics
Use reset ip statistics to clear IP traffic statistics.
Syntax
In standalone mode:
reset ip statistics
In IRF mode:
reset ip statistics [ slot slot-number ]
Views
User view
Predefined user roles
network-admin
Parameters
slot slot-number: Specifies an IRF member device by its member ID. If you do not specify a member device, this command clears IP traffic statistics for all member devices. (In IRF mode.)
Usage guidelines
Use this command to clear history IP traffic statistics before you collect IP traffic statistics for a time period.
Examples
# Clear IP traffic statistics.
<Sysname> reset ip statistics
display ip interface
reset tcp statistics
Use reset tcp statistics to clear TCP traffic statistics.
Syntax
reset tcp statistics
Views
User view
Predefined user roles
network-admin
Examples
# Clear TCP traffic statistics.
<Sysname> reset tcp statistics
reset udp statistics
Use reset udp statistics to clear UDP traffic statistics.
Syntax
reset udp statistics
Views
User view
Predefined user roles
network-admin
Examples
# Clear UDP traffic statistics.
<Sysname> reset udp statistics
Related commands
display udp statistics
tcp mss
Use tcp mss to set the TCP maximum segment size (MSS).
Use undo tcp mss to restore the default.
Syntax
tcp mss value
undo tcp mss
Default
The TCP MSS is not set.
Views
Interface view
Predefined user roles
network-admin
Parameters
value: Specifies the TCP MSS in bytes. The value range for this argument is 128 to 1610.
Usage guidelines
The MSS option informs the receiver of the largest segment that the sender can accept. Each end announces its MSS during TCP connection establishment. If the size of a TCP segment is smaller than the MSS of the receiver, TCP sends the TCP segment without fragmentation. If not, TCP fragments the segment according to the receiver's MSS.
If you set the TCP MSS on an interface, the size of each TCP segment received or sent on the interface cannot exceed the MSS value.
This configuration takes effect only on TCP connections that are established after the configuration and not on the TCP connections that already exist.
This configuration is effective only on IP packets. If MPLS is enabled on the interface, do not set the TCP MSS on the interface.
Examples
# Set the TCP MSS to 300 bytes on GigabitEthernet 1/0/1.
<Sysname> system-view
[Sysname] interface gigabitethernet 1/0/1
[Sysname-GigabitEthernet1/0/1] tcp mss 300
tcp path-mtu-discovery
Use tcp path-mtu-discovery to enable TCP path MTU discovery.
Use undo tcp path-mtu-discovery to disable TCP path MTU discovery.
Syntax
tcp path-mtu-discovery [ aging age-time | no-aging ]
undo tcp path-mtu-discovery
Default
TCP path MTU discovery is disabled.
Views
System view
Predefined user roles
network-admin
Parameters
aging age-time: Specifies the aging time for the path MTU, in the range of 10 to 30 minutes. The default aging time is 10 minutes.
no-aging: Does not age out the path MTU.
Usage guidelines
After you enable TCP path MTU discovery, all new TCP connections detect the path MTU. The device uses the path MTU to calculate the MSS to avoid IP fragmentation.
After you disable TCP path MTU discovery, the system stops all path MTU timers. The TCP connections established later do not detect the path MTU, but the TCP connections previously established still can detect the path MTU.
Examples
# Enable TCP path MTU discovery and set the path MTU aging time to 20 minutes.
<Sysname> system-view
[Sysname] tcp path-mtu-discovery aging 20
tcp syn-cookie enable
Use tcp syn-cookie enable to enable SYN Cookie to protect the device from SYN flood attacks.
Use undo tcp syn-cookie enable to disable SYN Cookie.
Syntax
tcp syn-cookie enable
undo tcp syn-cookie enable
Default
SYN Cookie is disabled.
Views
System view
Predefined user roles
network-admin
Usage guidelines
A TCP connection is established through a three-way handshake:
1. The sender sends a SYN packet to the server.
2. The server receives the SYN packet, establishes a TCP semi-connection in SYN_RECEIVED state, and replies with a SYN ACK packet to the sender.
3. The sender receives the SYN ACK packet and replies with an ACK packet. Then, a TCP connection is established.
An attacker can exploit this mechanism to mount SYN flood attacks. The attacker sends a large number of SYN packets, but they do not respond to the SYN ACK packets from the server. As a result, the server establishes a large number of TCP semi-connections and cannot handle normal services.
SYN Cookie can protect the server from SYN flood attacks. When the server receives a SYN packet, it responds to the request with a SYN ACK packet without establishing a TCP semi-connection.
The server establishes a TCP connection and enters ESTABLISHED state only when it receives an ACK packet from the sender.
Examples
# Enable SYN Cookie.
<Sysname> system-view
[Sysname] tcp syn-cookie enable
tcp timer fin-timeout
Use tcp timer fin-timeout to set the TCP FIN wait timer.
Use undo tcp timer fin-timeout to restore the default.
Syntax
tcp timer fin-timeout time-value
undo tcp timer fin-timeout
Default
The TCP FIN wait timer is 675 seconds.
Views
System view
Predefined user roles
network-admin
Parameters
time-value: Specifies the TCP FIN wait timer in the range of 76 to 3600 seconds.
Usage guidelines
TCP starts the FIN wait timer when the state of a TCP connection changes to FIN_WAIT_2. If no FIN packet is received within the timer interval, the TCP connection is terminated.
If a FIN packet is received, TCP changes the connection state to TIME_WAIT. If a non-FIN packet is received, TCP restarts the timer and tears down the connection when the timer expires.
Examples
# Set the TCP FIN wait timer to 800 seconds.
<Sysname> system-view
[Sysname] tcp timer fin-timeout 800
tcp timer syn-timeout
Use tcp timer syn-timeout to set the TCP SYN wait timer.
Use undo tcp timer syn-timeout to restore the default.
Syntax
tcp timer syn-timeout time-value
undo tcp timer syn-timeout
Default
The TCP SYN wait timer is 75 seconds.
Views
System view
Predefined user roles
network-admin
Parameters
time-value: Specifies the TCP SYN wait timer in the range of 2 to 600 seconds.
Usage guidelines
TCP starts the SYN wait timer after sending a SYN packet. Within the SYN wait timer if no response is received or the upper limit on TCP connection tries is reached, TCP fails to establish the connection.
Examples
# Set the TCP SYN wait timer to 80 seconds.
<Sysname> system-view
[Sysname] tcp timer syn-timeout 80
tcp timestamps enable
Use tcp timestamps enable to enable carrying the TCP timestamp option in outgoing TCP packets.
Use undo tcp timestamps enable to disable carrying the TCP timestamp option in outgoing TCP packets.
Syntax
tcp timestamps enable
undo tcp timestamps enable
Default
The device adds the TCP timestamp option in outgoing TCP packets.
Views
System view
Predefined user roles
network-admin
Usage guidelines
The TCP timestamp option in TCP packets is used to calculate the RTT between two communicating devices. In some networks, it is required to prevent the intermediate devices from obtaining the TCP timestamps in packets passing through. Then you can disable carrying the TCP timestamp option in outgoing packets on a device at either end.
This command takes effect on TCP connections established only after the execution of the command.
Examples
# Enable carrying the TCP timestamp option in outgoing TCP packets.
<Sysname> system-view
[Sysname] undo tcp timestamps enable
tcp window
Use tcp window to set the size of the TCP receive/send buffer.
Use undo tcp window to restore the default.
Syntax
tcp window window-size
undo tcp window
Default
The size of the TCP receive/send buffer is 63 KB.
Views
System view
Predefined user roles
network-admin
Parameters
window-size: Specifies the size of the TCP receive/send buffer, in the range of 1 to 64 KB.
Examples
# Set the size of the TCP receive/send buffer to 3 KB.
<Sysname> system-view
[Sysname] tcp window 3
