[CentOS] network interface up but no data
Dominik Zyla
gavroche at gavroche.pl
Mon Oct 25 13:49:10 UTC 2010
On Fri, Oct 22, 2010 at 10:58:34AM +1100, Nat N wrote:
> On Thu, Oct 21, 2010 at 9:52 PM, Nat N <phenisha at gmail.com> wrote:
> > Hi List,
> >
> > I am running a x86_64 Centos server, after a reboot the network has decided to
> > not work.. this particular machine has 8 eth ports eth0-7. eth0 and eth3 were
> > bonded (mode 1 ) after reboot the bond did not work. It came up OK but no
> > data was passing through it. all other interfaces on the machine were working.
> >
> > I decided to remove the bond, so after removing the bond i was left with eth0
> > using the same IP as the bond used. however it still does the same thing,
> > it starts up with no errors but i cannot even ping the default gateway,
> > tcpdump shows nothing on the interface.
> >
> > I have made sure of the following
> > * no iptables installed
> > * kernel modules for the NIC are loaded with no errors
> > * the bond kernel module is not installed / all bond configs have been removed
> >
> > Below is some info on the interface, it should be noted that all others are OK
> > the only 2 that were having the issue are eth0 and eth3 (the ex-bonded ones)
> >
> > server1:/etc/sysconfig/network-scripts# ip route | grep 172.18
> > 172.18.16.0/24 dev eth0 proto kernel scope link src 172.18.16.1
> > default via 172.18.16.254 dev eth0
> >
> >
> > # ifconfig eth0
> > eth0 Link encap:Ethernet HWaddr 00:24:49:C8:66:98
> > inet addr:172.18.16.1 Bcast:172.18.16.255 Mask:255.255.255.0
> > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> > RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> > TX packets:7223 errors:0 dropped:0 overruns:0 carrier:0
> > collisions:0 txqueuelen:1000
> > RX bytes:0 (0.0 b) TX bytes:463918 (453.0 KiB)
> > Interrupt:226 Memory:dc000000-dc012800
> >
> >
> > If you look closely TX and RX are massively different, but I am not
> > seeing anything on tcpdump even there is a large number of TX packets.
> >
>
> Just some more information on this issue.
>
> I have tried different kernels and the same issue is still occurring.
>
> # ethtool eth0
> Settings for eth0:
> Supported ports: [ TP ]
> Supported link modes: 10baseT/Half 10baseT/Full
> 100baseT/Half 100baseT/Full
> 1000baseT/Full
> Supports auto-negotiation: Yes
> Advertised link modes: 10baseT/Half 10baseT/Full
> 100baseT/Half 100baseT/Full
> 1000baseT/Full
> Advertised auto-negotiation: Yes
> Speed: 1000Mb/s
> Duplex: Full
> Port: Twisted Pair
> PHYAD: 1
> Transceiver: internal
> Auto-negotiation: on
> Supports Wake-on: g
> Wake-on: d
> Link detected: yes
>
> #mii-tool -v eth0
> eth0: negotiated, link ok
> product info: vendor 00:08:18, model 54 rev 6
> basic mode: autonegotiation enabled
> basic status: autonegotiation complete, link ok
> capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD
> advertising: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control
>
>
> I am still racking my brains on what is causing this
Maybe you have problem with switch configuration instead of system one.
--
Dominik Zyla
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
URL: <http://lists.centos.org/pipermail/centos/attachments/20101025/0217c5d4/attachment.sig>
More information about the CentOS
mailing list