Hi Adam Thanks for first one how do you counted the header size as 27 bytes?? I have a doubt on second one that IOS-XR does padding even it has hello padding disable , atleast this is something which i can't see in ethereal.
Thanks Amit Dhamija ________________________________ From: Adam Vitkovsky <[email protected]> To: 'Dhamija Amit' <[email protected]>; [email protected] Sent: Friday, November 22, 2013 6:37 PM Subject: RE: [c-nsp] ISIS LSP-MTU and CLNS-MTU Hi Amit, Regarding LSP MTU: (I'd assume the default size is below 1500 so 1492 seems right). My notes from an old book: max LSP size = 1492 bytes - header = 27 bytes == 1465 bytes for TLVs. LSP ID contains 8bit fragment id = max 256 fragments. => 256*1465 to pack ip reachability. -assuming the first fragment will carry some other TLVs. ==>aprox 31,000 prefixes. My findings regarding CLSN MTU: In case the hello padding is disabled ISIS still sends IIH padded to the full interface MTU -3B until the adjacency is formed. XR 4.2.3 will form ISIS adjacency with a remote system if incoming IIH is max 5bytes larger than the interface CLNS MTU over which the IIH was received. adam _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
