ASR 9001 MPA OIR procedure

[Sam Preston]

Hello,

The Cisco documentation that I could find pertaining to MPA OIR on Cisco 9001 chassis is not 100% clear. I'm talking about this document:

http://www.cisco.com/c/en/us/td/docs/iosxr/asr9000/hardware-install/9001-hig/b-asr9001-hardware-installation-guide/b-asr9001-hardware-installation-guide_chapter_011.html#con_1380033

What does this document state? There are 3 types of OIR:

1) Hard OIR

Physical insertion without  typing software commands. The requirements for using this kind of OIR are pretty clear.
- You can remove a module.
- You can insert a 20G module if the bay was initially empty or if it was already holding a 20G module
- You can insert a 40G module if the bay was initially loaded with a 40G module

So if you want to replace a 2x10G module by a 4x10G module, this type of OIR cannot be used.

2) Managed OIR

Physical insertion with typing surrounding software commands.
- Shutdown the MPA with "hw-module subslot x/x/x shutdown" command.
- Replace the MPA
- Type the "no hw-module subslot x/x/x" command.

Same restrictions as for the hard OIR (replace with the same type of MPA, 20G or 40G). So if you want to replace a 2x10G module by a 4x10G module, this type of OIR cannot be used.

3) Soft OIR

From the above assertions, if you want to replace a 2x10G module by a 4x10G one, this is the only type of OIR that you can use!

But we have a problem... The explanation of this type of OIR is really scarce and fuzzy. Here is what the document explains:

Soft OIR uses the IOS XR hw-module subslot 0/0/1 reload, hw-module subslot 0/0/1 shutdown, and no hw-module subslot 0/0/1 shutdown commands to complete online insertion and removal.

QUESTION 1: in which order should they be issued and when to replace physically the MPA: after/before typing which commands? The only difference that I can see with the managed OIR is the "hw-module subslot 0/0/1 reload" command. When you make a shutdown then no shutdown of the module, doesn't it equal to a reload or isn't it even better? I don't understand what the "reload" is for.

A clarification would really be welcome. Or a link to a more accurate document (which I was unable to find).

QUESTION 2: is there also a way to check in which mode the MPA bay is currently working (20G or 40G mode)? Do we have a command for this?

Thanks a lot for your help!

[xthuijs · Accepted solution]

Hi Sam,

for a module (or linecard for that matter) replacement it is always a good idea to shut the interfaces, for convergence and signaling to peers, shutdown the module/linecard, replace it, and unshut/power up the module/linecard and bring the interfaces back.

When you replace non similar MPA's eg a 2 port with a 4 port, you just see the first 2 ports use the existing configuration and 2 new interfaces added. If you do the reverse, replace a 4 port with a 2 port. the previous 2 extra ports go into preconfigure mode and can be manually removed from config.

The hw module reload first is not necessary.

the reload command for the module or linecard will do a some cleanup like tcp rst, interface signaling and what have you, but you can achieve the same thing by shutting the interfaces.

So soft and managed OIR are pretty much the same thing really with an extra step of some signaling to peers that we are going to bring that module down.

cheers

xander

[Sam Preston]

Hi Xander,

Always a pleasure to read you, since you provide valuable information that we can't find in the docs ;-)
Definitely this explanation is more clear than the official documentation. In my case I was just replacing an unused 2x10G module by a 4x10G one. So soft shut was not needed. But the "soft" vs "managed" OIR was not clear in that the doc was saying that replacing a 20G module by a 40G one was not possible with the managed OIR. In the end what I did (before getting your answer): hw-module subslot 0/0/1 reload, hw-module subslot 0/0/1 shutdown, and no hw-module subslot 0/0/1 shutdown. Everything OK with this procedure.

Thanks.

Cheers.

[xthuijs]

hey sam, ah thanks haha!! :) ok good deal glad to hear it is all working (out)!

it is always "nicest" to do a managed OIR as much as possible, but you could be "rough" with it also, which relies on other events (eg signal loss, proto timer expiries) for peers to detect the absence of this OIR'ing end.

enjoy! :)

cheers!

xander