Migrating those SVIs from IOS (7604) to IOS-XR (ASR9010)

[amaurisrm23]

Hi Folks,

I’m wondering what’s the recommended solution for migrating SVIs with HSRP from IOS to IOS-XR. I have little experience with IOS-XR but as per some Cisco documentation there’s no way to create similar concept of SVIs. I would like to have some insights about how to approach this escenario. As of now I’m just thinking to aggregate most as possible with 9300s for assuring a smooth transition until I figure out another way to do it.

Please any idea would be very much appreciated.

Thanks,

Amauris

[decode.chr13]

Hello,

I think is the same as in IOS, except the hierarchy where you set it up.

Here is a short example:
https://community.cisco.com/t5/networking-documents/basic-hsrp-configuration-on-cisco-ios-xr/ta-p/3147683

You can even do it as a transition path between 7604 and 9010, but you need to take care of the version 1/2 and authentication if you have one (I would temporarily drop auth in the migration steps and implement it after the HSRP is on both 9010).

Cheers

[amaurisrm23]

Thanks, so far I'm not using Auth.

[philclemens1835]

More info would help.  When you say "SVI", then I assume your physical interface is non-routed and in a VLAN with an SVI, and then you're running HSRP with the SVI.  As mentioned in the other reply, if you're simply going to move to routed interfaces on XR and run HSRP on those routed interfaces, then you configure that under the "router hsrp" area.

If you're looking to also replicate the VLAN/SVI environment, that is accomplished through bridge domains and bridge domain interfaces.

[amaurisrm23]

Hi philclemens1835,

You got it right, I have a switchport allowing some VLANs and then SVI with HSRP for each one of the SVIs. I was thinking to go that way with BDIs but I was just wondering if it was the recommended solution in a Service Provider environment. I can also convert the segment DIST-CORE to L3 and just keep the SVIs in a Cat 9300 for simplifying the L2 domain and isolate it one layer down away from the Core routers. Does it make sense?

[philclemens1835 · Accepted solution]

I would definitely go with tagged subinterfaces and BVI's in that case.  I've also noticed that Cisco is promoting more the concept of using BDI's/BVI's for all layer 3 functions in the service provider routers, so this is likely becoming the best practice in general.

Here's a very basic, untested, and not-quite-ready-for-primetime sample of the general config areas involved, to give you an idea.

interface BVI10
 ipv4 address 10.10.10.2 255.255.255.248

interface GigabitEthernet0/3/0/0.1 l2transport
 encapsulation dot1q 10

l2vpn
 bridge group TEST
  bridge-domain TEST
   interface GigabitEthernet0/3/0/0.1
   routed interface BVI10

router hsrp
 interface BVI10
  address-family ipv4
   hsrp
    address 10.10.10.1

[smilstea]

Depending on if the BVI only lives in the VLAN or not you may need the rewrite ingress tag pop 1 symmetric command. This has two functions, to pop the tag and on egress add the tag.

Everything else is good.

Sam

[philclemens1835 · Accepted solution]

Thanks Sam.  Forgot that part.

[pigallo]

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@amaurisrm23 wrote:

Hi Folks,

I’m wondering what’s the recommended solution for migrating SVIs with HSRP from IOS to IOS-XR. 

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Hello,

with HSRP i suggest to use BVI under XR, cause it's supported interface type and it is easy to implement with any L2 service that requires multiaccess segment reachability among routers in the same HSRP group.

Regards