Re: last-hop routers, raising the MTU
mogul (Jeffrey Mogul) Tue, 12 December 1989 02:27 UTC
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From: mogul (Jeffrey Mogul)
Message-Id: <8912120227.AA06895@acetes.pa.dec.com>
Date: 11 Dec 1989 1827-PST (Monday)
To: jnc@PTT.LCS.MIT.EDU (Noel Chiappa)
Cc: mtudwg
Subject: Re: last-hop routers, raising the MTU
In-Reply-To: jnc@PTT.LCS.MIT.EDU (Noel Chiappa) / Sun, 10 Dec 89 22:55:41 EST.
<8912110355.AA25661@PTT.LCS.MIT.EDU>
Whoa! I don't think your assertion that the last hop router will know the host's MTU is correct. Routers have to be able to receive and send the MTU on any interface, but they aren't required to know what any host is using (and have no way of finding that info out anyway). The rule is that 'a host must not send a larger datagram [than 576] without explicit knowledge or prior arrangement with the destination host'. This puts the onus on the end hosts, and frees the routers from getting involved in the game. It is perfectly possible to send a packet to a host that's bigger than the host is ready to receive.... Noel, you're confusing MTU and MSS. The assertion is correct, ignoring the possibility of translucent bridges, or else how could fragmentation possibly work?! -Jeff
- last-hop routers, raising the MTU smb
- Re: last-hop routers, raising the MTU Noel Chiappa
- Re: last-hop routers, raising the MTU Philippe Prindeville
- Re: last-hop routers, raising the MTU Noel Chiappa
- Re: last-hop routers, raising the MTU Jeffrey Mogul