Re: bad tcp cksum on outgoing packets

From: Ruslan Ermilov (ru_at_freebsd.org)
Date: 08/12/04

  • Next message: Robert Watson: "Re: bad tcp cksum on outgoing packets"
    Date: Thu, 12 Aug 2004 16:09:17 +0300
    To: Chris Stenton <jacs@gnome.co.uk>
    
    
    

    [Cc: freebsd-net]

    On Thu, Aug 12, 2004 at 12:50:58PM +0100, Chris Stenton wrote:
    > I have just been doing some debugging on my 5.2.1 box and noticed that
    > outgoing tcp packets on the box are coming up with bad checksums on
    > tcpdump. I am using the nge interface.
    >
    > Here is a sample output.
    >
    > 12:44:29.458021 0:4:e2:10:60:83 0:c:6e:4e:a0:cc ip 82:
    > hawk.gnome.co.uk.ssh > kite.gnome.co.uk.2167: P [bad tcp cksum 9420!]
    > 2071:2099(28) ack 753 win 65535 (DF) [tos 0x10] (ttl 64, id 35623, len
    > 68, bad cksum 0!)
    >
    > 12:44:29.642088 0:c:6e:4e:a0:cc 0:4:e2:10:60:83 ip 60:
    > kite.gnome.co.uk.2167 > hawk.gnome.co.uk.ssh: . [tcp sum ok] 753:753(0)
    > ack 2099 win 64956 (DF) (ttl 128, id 44852, len 40)
    >
    >
    > Any ideas whats going on as the packet does not seem to be resent?
    >
    You don't have hardware checksums enabled, do you? I barely
    recall they are incompatible with bpf(4).

    Cheers,

    -- 
    Ruslan Ermilov
    ru@FreeBSD.org
    FreeBSD committer
    
    



  • Next message: Robert Watson: "Re: bad tcp cksum on outgoing packets"

    Relevant Pages

    • Re: bad tcp cksum on outgoing packets
      ... [Cc: freebsd-net] ... > I have just been doing some debugging on my 5.2.1 box and noticed that ... > outgoing tcp packets on the box are coming up with bad checksums on ... Ruslan Ermilov ...
      (freebsd-current)
    • bad tcp cksum on outgoing packets
      ... I have just been doing some debugging on my 5.2.1 box and noticed that ... outgoing tcp packets on the box are coming up with bad checksums on ... To unsubscribe, ...
      (freebsd-current)