Hi Peter, As I already pointed to Les, using an offset creates some holes in index space that we need to manage when extending a block.
Let's say that we have SRGB [100-199] (to simplify) and you divide your block in two so you will have topology #1 using [100-149] and topology #2 using [150-199] using an offset of 50. Now I need to add a 51th node in my network, I cannot use index 51 because it will overlap with topology#2 :(, so I will need to skip indexes from 51 to 100, and restarts my numbering with index 101. This management of holes is not automated. Best Regards, Stephane -----Original Message----- From: Peter Psenak [mailto:[email protected]] Sent: Tuesday, August 25, 2015 13:18 To: LITKOWSKI Stephane SCE/IBNF; Eric C Rosen; Pushpasis Sarkar; SPRING WG Subject: Re: [spring] SRGBs, indexes, and topologies within a domain Hi Stephane, On 8/25/15 12:58 , [email protected] wrote: > Hi Peter, > >>> 1. If a new topology is added by use of the MT features of an IGP, >>> then a new set of prefix-SIDs must be provisioned. This seems like >>> a major provisioning task. The alternative would be to have an SRGB >>> per topology; then when you add a new topology, you only have one >>> quantity to provision (or one per platform perhaps). I hear some >>> hand-waving about how easy it is to provision new prefix-SIDs for >>> every new topology, but ... > >> I will keep repeating myself that such provisioning can be made automatic, >> so the above point is not really convincing to me. > > Could you explain how ? Based on past discussions, it does not seem to be so > easy. simply by associating an offset and size from SRGP on a per topology basis. Example: SRGB 1600-24000 I would assume that when you start to assign your SIDs for the default topology, you would not pick random values, but start from the beginning. So let' assume you are using 16001 to 16500 for nodes in default topology. Now you need to add a new topology. You configure and offset of 2k for it, so the advertised SIDs for the new topology would start from 18001. If we assume that the 2k would be a reasonable size for each topology you can have 4 topologies with 2k SIDs per topology. If for whatever reason you run out of the SID space in any topology, you can configure another offset for those SIDs which do not fit into the existing range for such topology. All of the above is internal to the node and no per topology SRGB advertisement is required. You advertise unique SID on a per prefix and per topology basis, but you do not need to configure each SID manually. Al you need to configure is the single prefix SID and per topology offset/size. It gives you the same simplicity for configuration as per topology SRGB, but without the need to advertise SRGB per topology. thanks, Peter > > > Best Regards, > > Stephane > > > > ______________________________________________________________________ > ___________________________________________________ > > Ce message et ses pieces jointes peuvent contenir des informations > confidentielles ou privilegiees et ne doivent donc pas etre diffuses, > exploites ou copies sans autorisation. Si vous avez recu ce message > par erreur, veuillez le signaler a l'expediteur et le detruire ainsi que les > pieces jointes. Les messages electroniques etant susceptibles d'alteration, > Orange decline toute responsabilite si ce message a ete altere, deforme ou > falsifie. Merci. > > This message and its attachments may contain confidential or > privileged information that may be protected by law; they should not be > distributed, used or copied without authorisation. > If you have received this email in error, please notify the sender and delete > this message and its attachments. > As emails may be altered, Orange is not liable for messages that have been > modified, changed or falsified. > Thank you. > > _________________________________________________________________________________________________________________________ Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration, Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci. This message and its attachments may contain confidential or privileged information that may be protected by law; they should not be distributed, used or copied without authorisation. If you have received this email in error, please notify the sender and delete this message and its attachments. As emails may be altered, Orange is not liable for messages that have been modified, changed or falsified. Thank you. _______________________________________________ spring mailing list [email protected] https://www.ietf.org/mailman/listinfo/spring
