I think it is inversed, cisco add the IP headers to the size you specified, and juniper include the IP header in the size you specified.
the problem appears when the packet arrives juniper interface with packet size larger than the interface MTU, which will drop the packet, while if this happened with cisco interface, it will fragment the packet. Juniper will fragment the packet when it arrives on interface with large MTU and leaves on interface with MTU smaler than the packet size. thanks Abdelghany ________________________________ From: Nilesh Khambal <nkham...@juniper.net> To: Flavio Schappo <fscha...@gmail.com> Cc: juniper-nsp@puck.nether.net Sent: Monday, March 16, 2009 8:27:55 PM Subject: Re: [j-nsp] MTU issues. Cisco includes ip and icmp header size in the total specified packet size. Payload in the case is 1510-20-8 = 1482 bytes. Juniper adds icmp and ip header to the payload size you specify. So 1510 becomes 1538 bytes of ip packet. Thanks, Nilesh On Mar 16, 2009, at 11:22 AM, "Flavio Schappo" <fscha...@gmail.com> wrote: > Hi > > Anybody have some explanation doc about MTU diferences between > JUNIPER and > CISCO? > > I think that I´m hitting some MTU issues where I have 2 ciscos worki > ng ping > with more them 1510 bytes and 2 Juniper or 1 juniper and 1 cisco are > not > working. > > Regards > > Flavio > _______________________________________________ > juniper-nsp mailing list juniper-nsp@puck.nether.net > https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
