I have seen this problem on various cisco switches (3550, 3560, 3750, 4948). They don't support GRE in hardware. The rest of the 49xx series and 45xx doesn't do it in hardware either As far as I know.
Under certain circumstances software handling even happens on the 6500. GRE tunnels can eat the cpu even if It is done partially in hardware. Enabling certain features will cause it to be done partially or completely in software on the 6500. Frankly a software router is better for GRE termination. The ASR1K series is great for it but it is technically still done in software. It just has a huge number of cores to do the encapsulation. Mack McBride | Network Architect | ViaWest, Inc. O: 720.891.2502 | mack.mcbr...@viawest.com | www.viawest.com | LinkedIn | Twitter | YouTube -----Original Message----- From: cisco-nsp [mailto:cisco-nsp-boun...@puck.nether.net] On Behalf Of Gert Doering Sent: Wednesday, July 15, 2015 3:24 PM To: a.l.m.bu...@lboro.ac.uk Cc: cisco-nsp@puck.nether.net Subject: Re: [c-nsp] GRE tunnel 8000kbit (8Mbit) limit issue Hi, On Wed, Jul 15, 2015 at 06:55:57PM +0000, a.l.m.bu...@lboro.ac.uk wrote: > (though more googling finds statement of no official support for GRE > even on 3750-X or that it cannot terminate GRE... well, the commands are > there and the tunnel works.. Classic IOS misfeature - "if the hardware cannot do it, just pretend everything is all right and try to do it in software". At least a word of warning would have been nice... (Sometimes it's handy to have a feature-in-software for management purposes, if you *know* there is not going to be much traffic over it, but the box need to tell you so) gert -- USENET is *not* the non-clickable part of WWW! //www.muc.de/~gert/ Gert Doering - Munich, Germany g...@greenie.muc.de fax: +49-89-35655025 g...@net.informatik.tu-muenchen.de This message contains information that may be confidential, privileged or otherwise protected by law from disclosure. It is intended for the exclusive use of the addressee(s). Unless you are the addressee or authorized agent of the addressee, you may not review, copy, distribute or disclose to anyone the message or any information contained within. If you have received this message in error, please contact the sender by electronic reply and immediately delete all copies of the message. _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
