Monitoring TCP Statistics for IPv6

Purpose

Display all TCP statistics (both IPv4 and IPv6). The TCP statistics are displayed only for the connections that are active within the context of the virtual router:

You can use the ip keyword to display only IPv4 statistics.
You can use the ipv6 keyword to display only IPv6 statistics.
You can use the brief keyword to display summary information or the detailed keyword to display extensive information.
You can use the diagnostic keyword to display diagnostic information collected on the TCP statistics in addition to the detailed information. This command shows information only for the connections that are active within the context of the virtual router in which you issue the command.

Note:

You must configure an IPv6 license using the license ipv6 command before using the IPv6 routing protocol configuration commands on the E Series router.
All IPv6 routing protocol-related configurations are removed from the virtual router when you issue the no ipv6 command.

Action

To display TCP statistics for IPv6:

host1#show ipv6 tcp statistics
TCP Global Statistics:
  Connections: 7358 attempted, 4 accepted, 7362 established
        0 dropped, 14718 closed
  Rcvd: 75923 total pkts, 53608 in-sequence pkts, 3120303 bytes
        0 chksum err pkts, 0 authentication err pkts, 0 bad offset pkts
        0 short pkts, 0 duplicate pkts, 0 out of order pkts
  Sent: 82352 total pkts, 44404 data pkts, 657095 bytes
        34 retransmitted pkts, 487 retransmitted bytes

TCP Session Statistics:
  Local addr: 0.0.0.0, Local port: 23
  Remote addr: 0.0.0.0, Remote port: 0
  State: LISTEN Authentication: None
  Rcvd: 4 total pkts, 0 in-sequence pkts, 0 bytes
        0 chksum err pkts, 0 bad offset pkts, 0 short pkts
        0 duplicate pkts, 0 out of order pkts
  Sent: 0 total pkts, 0 data pkts, 0 bytes
        0 retransmitted pkts, 0 retransmitted bytes

  Local addr: 192.168.1.250, Local port: 23
  Remote addr: 10.10.0.77, Remote port: 2170
  State: ESTABLISHED Authentication: None
  Rcvd: 61 total pkts, 34 in-sequence pkts, 41 bytes
        0 chksum err pkts, 0 bad offset pkts, 0 short pkts
        0 duplicate pkts, 0 out of order pkts
  Sent: 64 total pkts, 45 data

  Local addr: 192.168.1.250, Local port: 23
  Remote addr: 10.10.0.77, Remote port: 2170
  State: ESTABLISHED Authentication: None
  Rcvd: 61 total pkts, 34 in-sequence pkts, 41 bytes
        0 chksum err pkts, 0 bad offset pkts, 0 short pkts
        0 duplicate pkts, 0 out of order pkts
  Sent: 64 total pkts, 45 data pkts, 2304 bytes
        0 retransmitted pkts, 0 retransmitted bytes
 Local addr: 192.168.1.250, Local port: 23
  Remote addr: 192.168.1.139, Remote port: 1038
  State: ESTABLISHED Authentication: None
  Rcvd: 295 total pkts, 159 in-sequence pkts, 299 bytes
        0 chksum err pkts, 0 bad offset pkts, 0 short pkts
        0 duplicate pkts, 0 out of order pkts
  Sent: 281 total pkts, 210 data pkts, 3089 bytes
        0 retransmitted pkts, 0 retransmitted bytes

To display diagnostic information for all TCP statistics (both IPv4 and IPv6):

host1#show tcp statistics diagnostic
...
Global Diagnostic Data
    Unknown Connection log
Source address/port -> local port
         128.127.126.125/124 -> 8080  count: 3
         111.111.111.111/222 -> 3333  count: 4
# connection-reqs rejected: 0
    # connection-reqs pending: 0
    # sonewconn calls that fail: 0
...
  Diagnostics:
    PRU_ Operations counters:
      PRU_ATTACH: 0
      PRU_DETACH: 0
      PRU_BIND: 1
      PRU_LISTEN: 1
      PRU_CONNECT: 0
      PRU_ACCEPT: 0
      PRU_DISCONNECT: 0
      PRU_SHUTDOWN: 0
      PRU_RCVD: 0
      PRU_SEND: 0
      PRU_ABORT: 0
      PRU_CONTROL: 0
      PRU_SENSE: 0
      PRU_RCVOOB: 0
      PRU_SENDOOB: 0
      PRU_SOCKADDR: 0
      PRU_PEERADDR: 0
      PRU_CONNECT2: 0
      PRU_FASTTIMO: 0
      PRU_SLOWTIMO: 0
      PRU_PROTORCV: 0
      PRU_PROTOSEND: 0
    Wildcard Matches: 2
    Rcv'd Packets after connection closed: 0
    Connect request rejected: 0
    Connect request approval pending 0
    New soconnect failed 0
    # Write-Wakeups: 0
    # Read wakeups 0
    # receives after close 0
    Retransmit timer: 0
    Persistence timer: 0
    Keepalive timer: 0
    2MSL timer: 0
    tcpDisconnect()s: 0
    keep T/O pre-estab: 0
    tcpkeeptimeo_idle: 0
...
TCP Connection Event Log (most recent at bottom)
      TCPS_ELOG_PRU_ATTACH
      TCPS_ELOG_PRU_BIND

To display extensive information for all TCP statistics (both IPv4 and IPv6):

host1#show tcp statistics detailed
...

RST/SYN-Ack Protection is: ENABLED
    RSTs acked: 0
    ...Bogus RSTs: 0
    SYNs acked: 0
    ...Bogus SYNs: 0
    Data Insertions rejected: 0 
PMTUD Information:      PMTUD: ENABLED
    Administrative Minimum MTU: 512
    Administrative Maximum MTU: none
    Timer 1: 10 minutes
    Timer 2: 2 minutes
    # ICMP TooBigs: 0
    # ICMP TooBigs for unk. connection: 0
    PMTU Increase Attempts: 17
    Black Hole Detect Threshold: 50 retransmissions
...
MTU/MSS Information
    ENABLED on this connection
    MSS in effect: 536
    Calculated MSS to peer: 536
    MSS received from peer: 0
    Application set MSS: 0
    Xmit Interface MSS: 0
    MSS Sent to Peer: 0
    "ICMP DestUn, Frag Req'd and DF Set" messages: 0
    Number of attempts to increase PMTU: 0
    Time to next increase attempt: 0 seconds
    Black Hole Detection State: none 
...
Out-of-order Packet Queue Information

  Buffers Outstanding: 25
           High Water: 28
    Buffers discarded: 15
...
TCP-Paws is disabled

Meaning

Table 49 lists the show ipv6 tcp statistics command output fields.

Table 49: show ipv6 tcp statistics Output Fields

Field Name	Field Description
TCP Global Statistics Connections	attempted—Number of outgoing TCP connections attempted accepted—Number of incoming TCP connections accepted established—Number of TCP connections established
TCP Global Statistics Rcvd	total pkts—Total number of packets received in-sequence pkts—Number of packets received in sequence bytes—Number of bytes received chksum err pkts—Number of checksum error packets received authentication err pkts—Number of authentication error packets received bad offset pkts—Number of bad offset packets received short pkts—Number of short packets received duplicate pkts—Number of duplicate packets received out of order pkts—Number of packets received out of order
TCP Global Statistics Sent	total pkts—Total number of packets sent data pkts—Number of data packets sent bytes—Number of bytes sent retransmitted pkts—Number of packets retransmitted retransmitted bytes—Number of bytes retransmitted
Global Diagnostic Data Unknown Connection log	Includes the following global statistics: Source address/port – local port—Shows the 32 most recent TCP connection attempts that were rejected, including the remote node’s IP or IPv6 address and port, the local port for the connection attempt, and the number of identical attempts that have been received on that port in a row. The reason for rejection is not given. This information may be useful in tracking down DoS attacks. # connection-reqs rejected—Total number of connection attempts that have been rejected # connection-reqs pending—Current number of connection attempts that are pending, awaiting additional data from the peer # sonewconn calls that fail—Number of calls to sonewconn that have failed. This statistic often indicates that either a socket connection limit has been reached or that there was no memory to hold the socket data structures.
TCP Session Statistics	Local addr—Local address of the TCP connection Local port—Local port number of the TCP connection Remote addr—Remote address of the TCP connection Remote port—Remote port number of the TCP connection State—Current state of the TCP connection Authentication—Authentication status of the TCP connection
TCP Session Statistics Rcvd	total pkts—Total number of packets received on the TCP connection in-sequence pkts—Number of packets received in sequence on the TCP connection bytes—Number of bytes received on the TCP connection chksum err pkts—Number of checksum error packets received on the TCP connection bad offset pkts—Number of bad offset packets received on the TCP connection short pkts—Number of short packets received on the TCP connection duplicate pkts—Number of duplicate packets received on the TCP connection out of order pkts—Number of packets received out of order on the TCP connection
TCP Session Statistics Sent	total pkts—Total number of packets sent on the TCP connection data pkts—Number of data packets sent on the TCP connection bytes—Number of bytes sent on the TCP connection retransmitted pkts—Number of packets retransmitted on the TCP connection retransmitted bytes—Number of bytes retransmitted on the TCP connection
PRU_ Operations counters	Number of calls for each of the indicated PRU_operations within the TCP service API. These are per-connection statistics.
Wildcard Matches	Number of packets received that matched this TCP connection due to wildcard matching. Matching is expected for listening server connections, such as Telnet, but is not expected for established connections. This is a per-connection statistic.
Rcv'd Packets after connection closed	Number of packets received on the connection after the connection has been closed (and before the data structure gets removed). This is a per-connection statistic.
Connect request rejected	Number of times an incoming connection request was not approved. This is a per-connection statistic.
Connect request approval pending	Number of times that an incoming connection request was held pending, waiting for a subsequent packet. This is a per-connection statistic.
New soconnect failed	Number of times a SONEWCONN() was tried on a listening connection and failed. This is a per-connection statistic.
# Write-Wakeups	Number of times a “ write wakeup” occurred on the connection. This is a per-connection statistic.
# Read wakeups	Number of times a “ read wakeup” occurred on the connection. This is a per-connection statistic.
# receives after close	Number of packets received with data after the connection entered the close-wait state. This is a per-connection statistic.
Retransmit timer	Current value of the retransmit timer
Persistence timer	Current value of the persistence timer
Keepalive timer	Current value of the keepalive timer
2MSL timer	Current value of the 2MSL (max segment lifetime) timer
tcpDisconnect()s	Number of times BsdTcp::tcpDisconnect() was called. This is a per-connection statistic.
keep T/O pre-estab	Number of times the keepalive timer expired before the connection reached the established state. This is a per-connection statistic.
tcpkeeptimeo_idle	Number of times the keepalive timer popped, but no keepalive was sent because of connection idle-time considerations. This is a per-connection statistic.
TCP Connection Event Log (most recent at bottom)	Event log for the TCP connection. It shows the last 32 events that occurred on the connection. The most recent event is at the bottom of the list. This is per-connection data. TCPS_ELOG_PRU_ATTACH TCPS_ELOG_PRU_BIND The following events can be recorded: Fast Timeout—Did a PRU_CONNECT 2MSL Timeout—Did a PRU_CONNECT2 Retransmit Timeout—Did a PRU_DISCONNECT Persist Timeout—Did a PRU_ACCEPT Received FIN packet—Did a PRU_SHUTDOWN Received SYN packet—Did a PRU_RCVD Received Retransmission—Did a PRU_SEND Transmit a FIN packet—Did a PRU_ABORT Transmit a SYN packet—Did a PRU_SENSE Retransmit a packet—Did a PRU_RCVOOB Did a PRU_ATTACH—Did a PRU_SENDOOB Did a PRU_DETACH—Did a PRU_SOCKADDR Did a PRU_BIND—Did a PRU_PEERADDR Did a PRU_LISTEN—The keepalive timer popped. An 8-bit argument that describes how the timer was handled: Ignored because the session was not established (that is, not in the OPEN state) Ignored due to idle-timeout considerations A packet was sent Ignored because the connection did not have the keepalive option set OR the connection was in the process of closing
RST/SYN-Ack DoS Protection	Specifies when this function is enabled: RSTs acked—Number of RSTs received and then acknowledged by the TCP stack. Note: This count is maintained even when the protection functions are disabled. The value indicates the count of packets that would have been acknowledged if the protections were enabled. Providing this information can help determine whether attacks are occurring. Bogus RSTs—Number of RSTs that were judged to be invalid (that is, their timer expired) and therefore ignored SYNs acked—Number of SYNs received and then acknowledged by the TCP stack. Note: This count is maintained even when the protection functions are disabled. The value indicates the count of packets that would have been acknowledged if the protections were enabled. Providing this information can help determine whether attacks are occurring. Bogus SYNs—Number of RSTs that were judged to be invalid (that is, their timer expired) and therefore ignored Data Insertions rejected—Number of packets received and dropped because they are believed to have been inserted by an attacker Note: This count is maintained even when the protection functions are disabled. The value indicates the count of packets that would have been rejected if the protections were enabled. Providing this information can help determine whether attacks are occurring.
PMTUD information	Information regarding path MTU discovery: PMTUD—Status of path MTU discovery on the virtual router: enabled or disabled Administrative Minimum MTU—Minimum MTU that is enabled on any connection; a value of “ none” indicates that the minimum is zero (0) Administrative Maximum MTU—Maximum MTU that is enabled on any connection; a value of “ none” indicates that the maximum is 65535 Timer 1—Amount of time the virtual router waits after receiving an ICMP Too Big message before attempting to increase the path MTU Timer 2—Amount of time the virtual router waits after successfully increasing the MTU before attempting to increase it more # ICMP TooBigs—Number of ICMP Too Big messages that the router has received. When PMTU is disabled, this counter does not increase. # ICMP TooBigs for unk. connection—Number of ICMP Too Big messages that the router has received for TCP connections that do not exist. When PMTU is disabled, this counter does not increase. PMTU Increase Attempts—Number of attempts the router has made to increase the PMTU Black Hole Detect Threshold—Number of successive transmissions that must occur on a connection before that connection treats retransmissions as indications that something is wrong Override MSS—MSS that is advertised to peers, overriding the MSS that is derived from the interface MTU. This line does not appear in the output if you do not set the value.
MTU/MSS information	Information regarding path MTU/MSS: PMTU—Status of MTU/MSS on this virtual router: enabled or disabled MSS in effect—MSS currently being used for transmission to the peer. This number changes while various network events occur to cause the router to increase or decrease its estimate of the MSS. Calculated MSS to peer—MSS that path MTU discovery has calculated (if PMTUD is enabled) to the peer MSS received from peer—MSS that the peer received in a TCP MSS option. If no option is received, the value is zero (0). Application set MSS—MSS that an application might have set for the connection Xmit Interface MSS—MSS for the interface used to transmit packets to the peer; calculated as the interface MTU minus the size of the TCP and IP headers. MSS Sent to Peer—MSS that has been advertised to the peer “ICMP DestUn, Frag Req’d and DF Set” messages—Number of ICMP “Destination Unreachable: Fragmentation Required and DF set” messages that the router has received Number of attempts to increase PMTU—Number of times the router has attempted to increase the PMTU by probing with a packet that is larger than the known MTU Time to next increase attempt—Amount of time, in seconds, until the router retries to increase the MTU Black Hole Detection State—State of the black hole detection mechanism: none, detecting, probable, or unknown
Out-of-Order Packet Queue Information	Information regarding packet queue buffers: Buffers Outstanding—Number of buffers currently on the connection reordering queue High Water—Most buffers that have ever been on the connection reordering queue Buffers discarded—Number of buffers that were discarded because keeping them would have exceeded the connection maximum
TCP PAWS is [enabled/disabled]	Status of the TCP PAWS option; enabled indicates that PAWS is functioning normally (default mode) for TCP segments; disabled indicates that PAWS is disabled for TCP segments

Monitoring TCP Statistics for IPv6

Purpose

Action

Meaning

Related Documentation