IOS to Junos (I2J) Tips
IOS to Junos (I2J) Tips

Troubleshooting at layer4 with TCP IPv4 and IPv6

‎03-29-2012 09:02 AM

Hello fellow J-net community

 

See below on a neat troubleshooting command  for TCP and Layer4, I use it a lot for troubleshooting BGP peer establishment.

 

IOSJunOSPurpose and Use
show tcp briefshow system connectionsshow status  of IPv4 and ipv6 activity in terms of layer 4 session establisment

show tcp brief all

show system connections extensiveshow status  of IPv4 and ipv6 activity in terms of layer 4 session establisment with more details useful for troubleshooting at layer 4
1 REPLY 1
IOS to Junos (I2J) Tips

Re: Troubleshooting at layer4 with TCP IPv4 and IPv6

‎03-29-2012 09:04 AM

See sample outputs from a Cisco and Juniper Router

 

IOS

#show tcp brief
TCB       Local Address               Foreign Address             (state)
8948D598  2001:470Smiley Very Happy925:5EEE::1.61967 2001:470Smiley Very Happy925:5EEE::2.179   CLOSED
894F0B3C  63.245.30.153.23            mail.columbusgrenada..23675 ESTAB
883A5FE8  ns.6brent.info.179          63.245.30.56.65184          ESTAB
895999C0  10.40.40.1.26766            10.40.40.2.179              ESTAB
8959EE3C  2001:470:5:15C::1.179       2001:470:4:8E7::2.58094     ESTAB

 

JunOS

show system connections              
Active Internet connections (including servers)
Proto Recv-Q Send-Q  Local Address                                 Foreign Address                               (state)
tcp4       0     52  63.245.30.56.22                               63.245.66.12.19659                            ESTABLISHED
tcp4       0      0  63.245.30.56.65184                            63.245.30.25.179                              ESTABLISHED
tcp46      0      0  *.80                                          *.*                                           LISTEN
tcp4       0      0  *.6161                                        *.*                                           LISTEN
tcp4       0      0  *.38                                          *.*                                           LISTEN
tcp4       0      0  128.0.0.1.33001                               128.0.0.1.59887                               ESTABLISHED
tcp4       0      0  128.0.0.1.59887                               128.0.0.1.33001                               ESTABLISHED