slow download, quick upload

[User Patrice]

Hello

I ve checked for errors on the bsd side:
fxp0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=8<VLAN_MTU>
        inet 10.10.20.1 netmask 0xffffff00 broadcast 10.10.20.255
        ether 00:e0:18:53:3b:98
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active

Name    Mtu Network       Address              Ipkts Ierrs    Opkts Oerrs  Coll
fxp0   1500 <Link#1>      00:e0:18:53:3b:98  3104396     0  4232416     0     0
fxp0   1500 10.10.20/24   servidea           3374935     -  2492476     -     -


The error counter is 0 too on the other PC.