Continuing the theme of showing what show commands can do, let’s look at show run
for a bit.
A Cisco configuration can range from dozens of lines to thousands depending on what is setup on the router so here are some tips to help you control exactly what you are looking at.
One of the most useful filters is the interface
keyword, this lets you show just the configuration for a particular interface. Incidentally the fact that PT doesn’t support this command is one of things I find most frustrating about the tool.
R01#show run interface g2.254
Building configuration...
Current configuration : 100 bytes
!
interface GigabitEthernet2.254
encapsulation dot1Q 254
ip address 10.0.254.1 255.255.255.0
end
You can also use the partition
keyword to show specific configuration for routing processes, or things like ACLs.
R01#show running-config partition router ospf 1
Building configuration...
Current configuration : 134 bytes
!
Configuration of Partition - router ospf 1
!
!
!
!
!
!
router ospf 1
router-id 1.1.1.1
network 10.1.2.0 0.0.0.255 area 0
We can also search the output by pressing /
at the --more--
pager and typing a search term. This actually works for all show commands though it is usually the most useful with viewing configs.
R01#show run
Building configuration...
Current configuration : 4356 bytes
!
! Last configuration change at 06:57:42 UTC Mon Feb 6 2017
!
version 16.4
service timestamps debug datetime msec
service timestamps log datetime msec
no platform punt-keepalive disable-kernel-core
platform console serial
!
hostname R01
!
boot-start-marker
boot-end-marker
!
!
vrf definition Mgmt-intf
!
address-family ipv4
exit-address-family
!
address-family ipv6
/router
filtering...
router ospf 1
router-id 1.1.1.1
network 10.1.2.0 0.0.0.255 area 0
If you want to include linenumbers we can use the linenum
keyword, this can be handy for reference purposes. You can use this with viewing the startup-config as well.
R01#show run linenum
Building configuration...
Current configuration : 4286 bytes
1 : !
2 : ! Last configuration change at 03:44:31 UTC Mon Feb 6 2017
3 : !
4 : version 16.4
5 : service timestamps debug datetime msec
6 : service timestamps log datetime msec
7 : no platform punt-keepalive disable-kernel-core
8 : platform console serial
9 : !
10 : hostname R01
11 : !
12 : boot-start-marker
13 : boot-end-marker
14 : !
15 : !
16 : vrf definition Mgmt-intf
17 : !
18 : address-family ipv4
19 : exit-address-family
20 : !
21 : address-family ipv6
I’ll skip the example but the brief
keyword will skip the certificate information in the running config which can help clean up the output a bit.
Lastly we can use the all
keyword so the router will show all the default configuration that is normally not shown. This can be useful to remind yourself how something is configured by default.
R01#show run all | sec Gigabit.*254
interface GigabitEthernet2.254
encapsulation dot1Q 254
ip address 10.0.254.1 255.255.255.0
ip redirects
ip unreachables
ip proxy-arp
ip mtu 1500
ip pim join-prune-interval 60
ip pim dr-priority 1
ip pim query-interval 30
ip mfib forwarding input
ip mfib forwarding output
ip mfib cef input
ip mfib cef output
no ip flowspec
ip cef accounting non-recursive internal
ip load-sharing per-destination
ip route-cache
ip split-horizon
ip igmp last-member-query-interval 1000
ip igmp last-member-query-count 2
ip igmp query-max-response-time 10
ip igmp v3-query-max-response-time 10
ip igmp version 2
ip igmp query-interval 60
ip igmp tcn query count 2
ip igmp tcn query interval 10
no shutdown
no medium p2p
ipv6 nd reachable-time 0
ipv6 nd ns-interval 0
ipv6 nd dad attempts 1
ipv6 nd dad loopback detect
ipv6 nd prefix framed-ipv6-prefix
ipv6 nd nud igp
no ipv6 nd ra solicited unicast
ipv6 nd ra lifetime 1800
ipv6 nd ra interval 200
ipv6 redirects
ipv6 unreachables
ipv6 mfib forwarding input
ipv6 mfib forwarding output
ipv6 mfib cef input
ipv6 mfib cef output
no ipv6 flowspec
mpls mtu 1500
mpls mldp
no snmp trap link-status
autonomic
arp timeout 14400
no h323-gateway voip interface
no bgp-policy accounting input
no bgp-policy accounting output
no bgp-policy accounting input source
no bgp-policy accounting output source
no bgp-policy source ip-prec-map
no bgp-policy source ip-qos-map
no bgp-policy destination ip-prec-map
no bgp-policy destination ip-qos-map