TCP MSS on PIX

Yesterday, as a result of my Linux-based router/server’s breakdown I had to get on good terms with Cisco PIXes, as the only way to quickly restore connectivity with the world was to bring an ancient PIX-501 (software version 6.3(3)) home. Setting it up went quite well, who knows, maybe I’ll like them more from now on? :D But that’s not what I wanted to write about… ;) At the beginning, everything worked fine and problems started to emerge when I tried to view a certain page of my domain’s web administration panel – it didn’t work in IE and FF, while an hour later, from a different Internet link, everything was just fine.

Quickly googling the keywords I found an article at cisco.com regarding MSS problems. I didn’t actually find a direct solution there, but I did find inspiration :D I entered

sysopt connection tcpmss 1492

in global configuration mode and since then, everything works fine. I haven’t yet noticed any similar problems.

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