Replacing patterns in IOS XR router configuration

Aleksandar Vidakovic · ‎11-11-2015

Introduction

This functionality was introduced starting with IOS XR release 5.3.1 through CSCte81345.

Just like any other configuration command, it requires a "commit" command to have the configuration stored in sysdb. The "commit" is omitted in examples provided below for brevity.

Example 1: Replace Interface

Starting configuration:

!
hostname fella
group test
 interface 'GigabitEthernet*'
  description grouped
  mtu 500
 !
end-group
ipv4 access-list mylist
 10 permit tcp 10.20.30.40/16 host 1.2.4.5
 20 deny ipv4 any 1.2.3.6/16
!
class-map match-any c1
 match precedence 2 
 match dscp 7 
 end-class-map
!
policy-map p1
 class c1
  police rate 800000 bps 
  !
 !
 class class-default
  shape average 90000 bps 
 !
 end-policy-map
!
interface GigabitEthernet0/0/0/0
 description first
 ipv4 address 10.20.30.40 255.255.0.0
 shutdown
!
interface GigabitEthernet0/0/0/1
 shutdown
!
interface GigabitEthernet0/0/0/2
 description 10.20.30.40
 shutdown
!
interface GigabitEthernet0/0/0/3
 description 1020304050607080
 shutdown
!
interface GigabitEthernet0/0/0/4
 description 1.2.3.4.5.6.7.8
 shutdown
!
route-policy temp
  if ospf-area is 10.20.30.40 or source in (2.3.4.5/20) then
    pass
  endif
end-policy
!
router ospf 10
 cost 100
 area 200
  cost 200
  interface GigabitEthernet0/0/0/0
   transmit-delay 5
  !
 !
!
router bgp 1
!
end

Replace every occurence of "gigabitEthernet 0/0/0/0 with "loopback 450":

RP/0/0/CPU0:fella(config)#replace interface gigabitEthernet 0/0/0/0 with loopback 450           
Building configuration...
Loading.
232 bytes parsed in 1 sec (230)bytes/sec
RP/0/0/CPU0:fella(config-ospf-ar-if)#

Result (showing only the modified sections):

RP/0/0/CPU0:fella(config-ospf-ar-if)#show conf
Wed Feb 25 18:27:16.110 PST
Building configuration...
!! IOS XR Configuration 0.0.0
interface Loopback450
 description first
 ipv4 address 10.20.30.40 255.255.0.0
 shutdown
!
no interface GigabitEthernet0/0/0/0
router ospf 10
 area 200
  interface Loopback450
   transmit-delay 5
  !
  no interface GigabitEthernet0/0/0/0
 !
!
end

Example 2: Replace pattern

Staring from the same initial configuration as in example #1, replace every occurence of "10.20.30.40" with "100.200.250.225":

RP/0/0/CPU0:fella(config)#replace pattern '10.20.30.40' with '100.200.250.225'
Building configuration...
Loading.
434 bytes parsed in 1 sec (430)bytes/sec

Result (showing only the modified sections):

RP/0/0/CPU0:fella(config)#show conf
Thu Feb 26 09:00:11.180 PST
Building configuration...
!! IOS XR Configuration 0.0.0
ipv4 access-list mylist
 no 10
 10 permit tcp 100.200.250.225/16 host 1.2.4.5
!
interface GigabitEthernet0/0/0/0
 no ipv4 address 10.20.30.40 255.255.0.0
 ipv4 address 100.200.250.225 255.255.0.0
!
interface GigabitEthernet0/0/0/2
 no description
 description 100.200.250.225
!
!
route-policy temp
  if ospf-area is 100.200.250.225 or source in (2.3.4.5/20) then
    pass
  endif
end-policy
!
end

Example 3: Replace Pattern Using Regular Expressions

The desired wildcard effect can be produced using the more powerful "replace pattern", which can take POSIX compliant regular expressions. Take this config as start:

RP/0/0/CPU0:ios#sh run
Fri Feb 27 16:49:39.126 PST
Building configuration...
!! IOS XR Configuration 0.0.0
!! Last configuration change at Fri Feb 27 16:49:27 2015 by UNKNOWN
!
interface GigabitEthernet0/0/0/0
 ipv4 address 10.0.0.10 255.255.0.0
!
interface GigabitEthernet0/0/0/1
 ipv4 address 11.0.0.11 255.255.0.0
!
interface GigabitEthernet0/0/0/2
 ipv4 address 12.0.0.12 255.255.0.0
!
interface GigabitEthernet0/0/0/3
 ipv4 address 13.0.0.13 255.255.0.0
!
interface GigabitEthernet0/0/0/4
 ipv4 address 14.0.0.14 255.255.0.0
!
interface GigabitEthernet0/1/0/0
 ipv4 address 20.0.0.10 255.255.0.0
!
interface TenGigE0/3/0/0
 shutdown
!
interface TenGigE0/3/0/1
 shutdown
!
interface TenGigE0/3/0/2
 shutdown
!
interface TenGigE0/3/0/3
 shutdown
!
interface TenGigE0/3/0/4
 shutdown
!
interface TenGigE0/3/0/5
 shutdown
!
interface TenGigE0/3/0/6
 shutdown
!
end

Using replace pattern 'GigabitEthernet0/1/0/([0-4]*)' with 'TenGigE0/3/0/\1', interfaces GigabitEthernet0/0/0/0 through GigabitEthernet0/0/0/4 are replaced with TenGigE0/3/0/0 through TenGigE0/3/0/4:

RP/0/0/CPU0:ios(config)#replace pattern 'GigabitEthernet0/1/0/([0-4]*)' with 'TenGigE0/3/0/\1'  
Building configuration...
Loading.
485 bytes parsed in 1 sec (482)bytes/sec

Result:

RP/0/0/CPU0:ios(config-if)#show conf
Fri Feb 27 16:52:56.549 PST
Building configuration...
!! IOS XR Configuration 0.0.0
no interface GigabitEthernet0/1/0/0
no interface GigabitEthernet0/1/0/1
no interface GigabitEthernet0/1/0/2
no interface GigabitEthernet0/1/0/3
no interface GigabitEthernet0/1/0/4
interface TenGigE0/3/0/0
 ipv4 address 20.0.0.10 255.255.0.0
!
interface TenGigE0/3/0/1
 ipv4 address 21.0.0.11 255.255.0.0
!
interface TenGigE0/3/0/2
 ipv4 address 22.0.0.12 255.255.0.0
!
interface TenGigE0/3/0/3
 ipv4 address 23.0.0.13 255.255.0.0
!
interface TenGigE0/3/0/4
 ipv4 address 24.0.0.14 255.255.0.0
!
End

Example 4: Additional Syntax Check

If you want to be extra cautious and see the result before it's actually applied, you can use the dry-run option. This option immediately shows the final configuration, i.e. you don't have to run the "show conf" from the configuration mode to see the modified configuration.

RP/0/RSP0/CPU0:our9001(config)#replace pattern '1.1.1.1' with '2.2.2.2' dry-run
vrf VOICE
 address-family ipv4 unicast
  import route-target
   no 121:121
   2.2.2.2
  export route-target
   no 121:121
   2.2.2.2
interface tunnel-te10
 no autoroute destination 1.1.1.1
 autoroute destination 2.2.2.2
end

Tom Marcoen · ‎11-16-2015

Great new feature! I'm really looking forward to upgrading our ASRs to 5.3.x.

Brent Crier · ‎01-06-2016

Very cool. Although I'm not a fan that it removes the interface from the config when you place the interface. I think a better option would have been un-configure it.

RP/0/0/CPU0:ios(config)#replace pattern 'GigabitEthernet0/1/0/([0-4]*)' with 'TenGigE0/3/0/\1'

Aleksandar Vidakovic · ‎01-08-2016

hi Brent,

thanks for the feedback. We have decided for the removal because it was easier to implement and it was better serving the use case of virtual interfaces. You are bringing up a valid point in case of physical interfaces. Were you indeed referring to physical interfaces?

Regards,

Aleksandar

ciromarciano · ‎01-22-2018

Hi Aleksandar,

it is possible to use this command to change a range of interfaces?

An example: the goal is to move the configuration under interfaces GigabitEthernet 0/1/0/5 --> 0/1/0/10 to interface TenGigE 0/3/0/5 --> 0/3/0/10.

Thank you

Ciro