Re: [Lsr] [rt5.ietf.org #7080] System ID in ISIS

From: Lsr <lsr-bounces@ietf.org> on behalf of Les Ginsberg (ginsberg) <ginsberg=40cisco.com@dmarc.ietf.org>
Sent: 14 June 2022 17:29

Jaideep –

I am not aware that any standard formally defines a system-id of 0000.0000.0000 as invalid.
If there is, it would be an ISO specification – but a perusal of ISO 10589, ISO 8348, and ISO 7498 did not yield any such statement.
(I would be happy to be corrected if someone has a reference.)

>From a practical standpoint, the lack of agreement on this by all implementations should not represent a significant concern.
Schemes which automatically populate the system-id are typically based on the MAC address of some NIC on the box.
Another common strategy is to use the zero filled IP address of some loopback.
In either case all zeros will not be the result.

In cases where the systemid is explicitly configured, it is easy enough NOT to use all 0’s.

<tp>
Looking at draft-isis-yang-isis-cfg, it has a regex for system-id which if I reverse engineer it aright allows for all zero along with all [0-9a-fA-F]

Tom Petch

HTH

    Les

From: Lsr <lsr-bounces@ietf.org> On Behalf Of Jaideep Choudhary
Sent: Tuesday, June 14, 2022 8:00 AM
To: Tony Li <tony.li@tony.li>
Cc: support@ietf.org; lsr@ietf.org
Subject: Re: [Lsr] [rt5.ietf.org #7080] System ID in ISIS

Hi Tony,

I am not looking for technical support, but looking for IETF's perspective regarding the system id in IS-IS.

As per the RFC 3784 there is no mention about any invalid value in a system id.

Can you please confirm whether there is any such restriction to not to use a SYS ID of 0000.0000.0000 as per IETF standards ?

If this mailing address is not appropriate for answering this query, can you suggest/redirect me to the correct team from IETF ?

Thanks.

Regards
Jaideep

On Tue, Jun 14, 2022, 20:19 Tony Li <tony.li@tony.li<mailto:tony.li@tony.li>> wrote:

Hi,

Neither of these mailing lists are appropriate for technical support.  Please contact your vendors directly.

Tony

On Jun 14, 2022, at 12:12 AM, Jaideep Choudhary <jaideepchoudhary91@gmail.com<mailto:jaideepchoudhary91@gmail.com>> wrote:

Hi Team,

I would like to know, whether in IS-IS, a system id can be 0000.0000.0000 or it is an invalid value for sys I'd ?

As per ISO 10589 a system id can be of 1 to 8 bytes long, but doesn't mention explicitly whether SYS ID of 0000.0000.0000 could be invalid.

Also as per RFC 3784, it says System id is typically of 6 bytes, but doesn't talk about any invalid option.

The reason I am asking this is that Juniper defines a SYS ID of 0000.0000.0000 as invalid.

https://www.juniper.net/documentation/us/en/software/junos/is-is/topics/concept/is-is-routing-overview.html

This can cause issues in inter-operability as some vendors like Cisco doesn't define a SYS-ID of 0000.0000.0000 as invalid.

I would appreciate your response on this.

Regards

Jaideep Choudhary

On Mon, 13 Jun, 2022, 11:08 pm Cindy Morgan via RT, <support@ietf.org<mailto:support@ietf.org>> wrote:

Hi Jaideep,

You have reached the IETF Secretariat, which is the administrative branch of the IETF, and as such, we are not qualified to answer your technical questions.

You might have better luck if you try posing your question to the Link State Routing (LSR) Working Group (https://datatracker.ietf.org/wg/lsr/about/). LSR was formed by merging the ISIS and OSPF WGs and assigning all their existing adopted work at the time of chartering to LSR. Their mailing list address is lsr@ietf.org<mailto:lsr@ietf.org>.

Best regards,
Cindy

On Mon Jun 13 10:10:54 2022, jaideepchoudhary91@gmail.com<mailto:jaideepchoudhary91@gmail.com> wrote:
Hi Team,