Hi Les, Thanks for the response. Yes, i understand that it would require a lot of efforts and can take some years.
But as we discussed SYS ID 0 should be considered valid as Standard Documents doesn't define otherwise and at same time we should try to use a logical value as a SYS ID so we don't create inter-operability issues where a vendor doesn't consider it as valid. "What reason did the customer give for configuring a systemid of 0?" Customer had only a few Cisco nodes participating in the IS-IS , so they started configuring the sys id 0000.0000.0000 then 0000.0000.0001 and so on. Thanks a lot for your time and understanding. Regards Jaideep On Thu, 16 Jun, 2022, 12:57 am Les Ginsberg (ginsberg), <ginsb...@cisco.com> wrote: > Jaideep – > > > > I am not unsympathetic to problems encountered in the field. > > It isn’t always easy to get a customer to agree to what you and I might > easily agree makes sense. > > > > But, in this case, consider what might be required to get an unambiguous > standard defined: > > > > 1)We would have to establish consensus on whether 0 should/should not be > considered as valid > > > > 2)We would have to get the vendors whose implementations do not conform to > whatever is agreed upon in #1 to commit to changing their implementations > > > > 3)A standard would have to be written and work its way through the > approval process. This would most practically be an IETF draft as there is > no one actively updating ISO specs. > > > > All of this would take years – and at the end we would only have resolved > the use of a systemid for which there is no practical deployment case. > > > > I just don’t think this is worth the effort. > > > > What reason did the customer give for configuring a systemid of 0? > > > > Les > > > > *From:* Jaideep Choudhary <jaideepchoudhar...@gmail.com> > *Sent:* Tuesday, June 14, 2022 11:59 PM > *To:* Les Ginsberg (ginsberg) <ginsb...@cisco.com> > *Subject:* Re: [Lsr] [rt5.ietf.org #7080] System ID in ISIS > > > > Hi Les, > > > > We have recently experienced some issue in this regards on a vendor where > SYS ID of 0000.0000.0000 was not interpreted correctly. > > > > In a single area with level L1 and mutli-vendor setup, a Cisco node was > configured with SYS I'd of 0000.0000.0000. > > The other vendor node could not interpret 0000.0000.0000 as a system id > the way it does for other SYS IDs and there were some issues with the > system level command outputs. > > > > Modifying the SYS id on Cisco node did help, but it took a lot of time to > find the cause. > > > > When I talked about routing issues, what I meant was, that if for example > a Juniper node doesn't consider SYS ID of 0000.0000.0000 as legal, then it > may not install the LSP from the node with SYS ID=0. > > > > If it is directly connected node, then Juniper node may not form adjacency > and it can be found out easily, but if it is not directly connected node, > then it would take good amount of time to find the cause. > > > > That in turn can cause some issues. > > > > I also agree 100% that it doesn't make sense to make a SYS ID of 0, but > talking from an experience we had, it was configured. > > > > Since it is not defined as invalid as per standard documents, it also > makes sense to have uniformity across different implementations, so no such > issue occurs in multi-vendor setups. > > > > Also the reason of verifying this with IETF was to understand the reason > behind Juniper defining sys I'd as illegal. > > We wanted to confirm if SYS ID 0 is reserved for some other use ? > > > > I hope , I am able to make my point here. > > > > Really appreciate your time. > > Thanks ! > > > > Regards > > Jaideep > > > > > > On Wed, 15 Jun, 2022, 10:46 am Les Ginsberg (ginsberg), < > ginsb...@cisco.com> wrote: > > (Taking this offlist – BCC the WG) > > > > Jaideep – > > > > From a standards perspective I have provided you with what I know. > > > > To characterize this as something which can cause “serious routing issues” > is an exaggeration. > > Given that the same system ID cannot be used on more than one router, at > worst if you were in a deployment where an implementation did not accept a > systemid of 0000, all you would need to do is modify the config of a single > router. > > > > Assigning a systemid which has no relationship to the identity of the > equipment/configuration of the node isn’t practical – I don’t think any > thoughtful network manager would ever do such a thing. > > In my view you have lost perspective on this issue. > > > > Les > > > > > > *From:* Jaideep Choudhary <jaideepchoudhar...@gmail.com> > *Sent:* Tuesday, June 14, 2022 9:57 PM > *To:* Les Ginsberg (ginsberg) <ginsb...@cisco.com> > *Cc:* Tony Li <tony...@tony.li>; supp...@ietf.org; lsr@ietf.org > *Subject:* Re: [Lsr] [rt5.ietf.org #7080] System ID in ISIS > > > > Hi Les, > > > > Thanks for the quick response. > > > I also could not find anywhere in the standard documentation stating that > SYS ID of 0000.0000.0000 in IS-IS as invalid nor is there any restriction > to how to calculate the SYS ID. > > > > Yes, there are recommendations to use MAC or IP address to calculate the > SYS ID , so it remains unique in a routing domain, but *couldn't *be > found anywhere in the standard documentation, if SYS ID *must be derived > from these addresses only*. > > Having said that, in most of the cases, there would be very less > probability of SYS ID of 0000.0000.0000 being configured in a production > environment (as you also mentioned), but still, as there is no such > explicit restriction (in the standards ISO10589 or RFC 3784) to not to use > SYS ID: 0, so it can still be used as a valid SYS ID in the devices where > it is allowed to configure the NET/SYSTEM ID manually. > > > > So in that case if some device the setting of SYS ID being 0 is considered > as invalid or illegal, that can cause some serious routing issues in a > single area multi vendor setup in ISIS. > > *So, can we say that from Standards perspective SYS ID: 0000.0000.0000 is > a legal setting ?* > > > > Regards > > Jaideep > > > > On Tue, Jun 14, 2022 at 9:59 PM Les Ginsberg (ginsberg) < > ginsb...@cisco.com> wrote: > > 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. > > > > HTH > > > > Les > > > > *From:* Lsr <lsr-boun...@ietf.org> *On Behalf Of *Jaideep Choudhary > *Sent:* Tuesday, June 14, 2022 8:00 AM > *To:* Tony Li <tony...@tony.li> > *Cc:* supp...@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...@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 < > jaideepchoudhar...@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, <supp...@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. > > Best regards, > Cindy > > On Mon Jun 13 10:10:54 2022, jaideepchoudhar...@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 > > > > > > > > _______________________________________________ > Lsr mailing list > Lsr@ietf.org > https://www.ietf.org/mailman/listinfo/lsr > > > >
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