# [Solved] Single website fails to load through gateway

## seleste

This is the strangest issue I've run into in years of using various Linux distros as home gateway and file servers... Said server is running Gentoo Hardened, 2.6.39-hardened-r8. Hardened kernel settings are pretty much intact from defaults, with Grescurity set to Gentoo Hardened [Server] level. I'd provide more details but I'm not even sure where to begin pinning down this problem, so I'd like some suggestions. The problem is as follows:

On one computer in the network, when going through the Linux gateway, there is a single website (chan.sankakucomplex.com, likely NSFW at any moment) that fails to connect with a connection reset error in the browser. Other computers in the network have no such issues. If connecting with no cookies set from the domain, the initial page will load, but with no stylesheet information and no pictures. I suspect subsequent connections for those particular details are failing once the website's cookie is set. All browsers tried on this faulty computer have the same behaviour (IE, Firefox, Chrome). On the other hand, going through TOR has the page loading properly. Disabling cookies for that hostname also allows the page to load properly.

I've already tried removing all my particular iptables rules to only the most basic NAT masquerading stuff, with no apparent change. I've looked through syslog, messages and any logs I could think of and nothing seems to show up when attempting to load the page. Not really sure what to look at next.

I imagine something in the way the HTTP headers are formed and sent by the website once a cookie is acquired must trigger some security failsafe in the gateway. At this point I'm mostly curious as to why this particular website and computer are exhibiting this behaviour

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## seleste

As it turns out, it wasn't anything fancy -- my cable ISP's DHCP has a habit of providing garbage MTU values, and I had forgotten to override it to 1500 after reconfiguring my gateway for amd64.

Mystery solved.  :Embarassed: 

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