Comodo Anti-Virus download over IPv6
I've been having problems updating or downloading Comodo Anti-Virus over IPv6. I had been trying it out for a while and was quite please with it as a free offering but realised updates didn't work in my home environment.
The issue seemed to be down to the MTU setting for IPv6 traffic. The MTU is basically the size each chunk of data gets sent over the Internet. It is generally all handled automatically these days. The catch for me came as I'm using a 4-to-6 tunnel to provide IPv6 access (i.e. my ISP doesn't provide native IPv6, so I have to tunnel to another provider, SixXS, to get IPv6 Internet).
The SixXS tunnel by default operates an MTU of 1280, instead of the "normal" 1500. And whilst you can have this changed, you have to be careful of the tunnel overheads.
In order for computers on a network to connect to IPv6 machines, there has to be a router, which advertises itself and describes the networks it links. This means IPv6 is very easy to setup as this advertisements allow everything to be automatic - unless of course, it's not configured correctly. I'm using "radvd", a standard Linux daemon for router advertisement. You can force the MTU of the link by adding at the "interface" level:
AdvLinkMTU 1280;
This did the job for me and once again the Comodo web-site is working fine. I have no idea why it is only that web-site that has caused me issues but there we go, my network should be much cleaner as a result too.
The issue seemed to be down to the MTU setting for IPv6 traffic. The MTU is basically the size each chunk of data gets sent over the Internet. It is generally all handled automatically these days. The catch for me came as I'm using a 4-to-6 tunnel to provide IPv6 access (i.e. my ISP doesn't provide native IPv6, so I have to tunnel to another provider, SixXS, to get IPv6 Internet).
The SixXS tunnel by default operates an MTU of 1280, instead of the "normal" 1500. And whilst you can have this changed, you have to be careful of the tunnel overheads.
In order for computers on a network to connect to IPv6 machines, there has to be a router, which advertises itself and describes the networks it links. This means IPv6 is very easy to setup as this advertisements allow everything to be automatic - unless of course, it's not configured correctly. I'm using "radvd", a standard Linux daemon for router advertisement. You can force the MTU of the link by adding at the "interface" level:
AdvLinkMTU 1280;
This did the job for me and once again the Comodo web-site is working fine. I have no idea why it is only that web-site that has caused me issues but there we go, my network should be much cleaner as a result too.