Strange CVS problem

[Stephane Bortzmeyer <bortzmeyer@pasteur.fr>]

I try to catch up on all the last modifications for boot-floppies:

ezili:~/Debian-CVS/boot-floppies> cvs update
Warning: Remote host denied X11 forwarding, perhaps xauth program could not be 
run on the server side.
cvs server: Updating .

And then nothing happens during hours...

But cvs.debian.org does strange things. My ichains catch:

Packet log: input REJECT eth0 PROTO=6 209.81.8.242:65535 157.99.60.56:65535 
L=44 S=0x08 I=51113 F=0x00B6 T=54
Packet log: input REJECT eth0 PROTO=6 209.81.8.242:65535 157.99.60.56:65535 
L=44 S=0x08 I=56503 F=0x00B6 T=53

209.81.8.242 is cvs.debian.org, 157.99.60.56 is my machine. Why does CVS 
suddenly needs to send these packets???

Debian 2.1, kernel 2.1.132 on my side.