Hi Alejandro,I have a

Alejandro Rivera · ‎08-07-2015

Hello,

Straight to point, IOS allows route-target configuration as "0:N" format, but the IOS XE and XR wont allow that such configuration, supporting only 2-byte AS starting at 1 and 4-byte AS.

Output:

--------------------------------------------------------------------------------------------

NOM-ASR903(config-vrf-af)#route-target both 0:23
^
% Invalid input detected at '^' marker.

NOM-ASR903(config-vrf-af)#route-target both ?
ASN:nn or IP-address:nn Target VPN Extended Community

NOM-ASR903(config-vrf-af)#route-target both 0:2
^
% Invalid input detected at '^' marker.

NOM-ASR903(config-vrf-af)#exit

--------------------------------------------------------------------------------------------

- Is there any other way to configure an L3VPN with route-target "0:N" format or workaround?

Thanks in advance,

Best Regards,

Alejandro Rivera

Peter Paluch · ‎08-10-2015

Hi Alejandro,

I have a somewhat different observation: IOS-XE I am running allows using the RD and RT of 0:x while IOS does not.

It seems that the value of 0:x is a marginal value whose support (or lack thereof) is not universal even between different versions of the same IOS type. Being such a problematic value, I would rather avoid using it. You may find IOSes that will allow you to use it but other versions or IOS types may plainly refuse to process or configure it. Ultimately, you will end up forced to change it anyway.

Do you have any specific need to use 0 in the RD/RT?

Best regards,
Peter

Alejandro Rivera · ‎08-10-2015

Hi Peter,

Well, our engineering team knows that nobody should use such 0:X format. The things is, we encountered this situation in one of our client's networks, we suggested that the services using that format should be changed in a migration process, nevertheless we still need to install services on devices using IOS XE and XR, but they cant deliver services using the 0:X format.

What version of IOSXE did you use that allowed 0:X format for the RT config?

Best Regards,

Alejandro Rivera

Peter Paluch · ‎08-12-2015

Hi Alejandro,

I apologize for my late response.

The IOS-XE I've used was in fact a CSR1000v with 3.16 image.

CSR1000v(config)# do show ver | i Vers
Cisco IOS XE Software, Version 03.16.00.S - Extended Support Release
Cisco IOS Software, CSR1000V Software (X86_64_LINUX_IOSD-UNIVERSALK9-M), Version 15.5(3)S, RELEASE SOFTWARE (fc6)
CSR1000v(config)# vrf definition Test
CSR1000v(config-vrf)# rd 0:1
CSR1000v(config-vrf)# route-target 0:1
CSR1000v(config-vrf)# address-family ipv4
CSR1000v(config-vrf-af)# exit
CSR1000v(config-vrf)# exit
CSR1000v(config)# do show vrf
  Name                             Default RD            Protocols   Interfaces
  Test                             0:1                   ipv4

Best regards,
Peter

Alejandro Rivera · ‎08-12-2015

Hello Peter,

Thanks for the help, it was quite accurate. We did an upgrade to the ASR903, from 3.14 to 3.16, which delivered the solution. As an observation, version 3.10 allows this configuration too.

Now, the issue persists for the IOS XR.

Thanks again.

Best Regards,

Alejandro Rivera

IOS XR/XE Route-Target support "0":N format