Q: Why does my firewall hate the cambridge picturehouse?

[Jeremy Henty]

On Wed, Oct 22, 2008 at 12:02:44PM +0100, Richard wrote:

> I have had a similar problem  when the MTU was set incorrectly on my
> Internet port (using PPPoA modem  on a linux firewall). it was begin
> defaulted to a value too high.

Good idea, but it doesn't look like it.  On my Speedtouch modem:

    =>ip iflist
    Interface       GRP MTU  ...
    0  loop         1   1500 ...
    1  eth0         2   1500 ...
    2  PPPoA_1      0   1456 ...

and the OS itself:

    # ip link show
    1: lo: <LOOPBACK,UP,10000> mtu 16436 ...
    2: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 ...
    3: dummy0: <BROADCAST,NOARP> mtu 1500 ...
    4: sit0: <NOARP> mtu 1480 ...

An MTU of 1500 is standard, isn't it?

Regards, 

Jeremy Henty