* Re: routing bug?
[not found] <4EC648C9.8080405@uhulinux.hu>
@ 2011-11-18 12:48 ` Sven-Haegar Koch
2011-11-18 13:09 ` Eric Dumazet
0 siblings, 1 reply; 6+ messages in thread
From: Sven-Haegar Koch @ 2011-11-18 12:48 UTC (permalink / raw)
To: Pozsár Balázs
Cc: Linux-Kernel-Mailinglist, Tamási János, netdev
[-- Attachment #1: Type: TEXT/PLAIN, Size: 3834 bytes --]
Added netdev list to CC:, there you should have a higher chance of a
usefull answer.
On Fri, 18 Nov 2011, Pozsár Balázs wrote:
> Hi all,
>
> I have been struggling with this not easily reproducible issue since a while.
> I am using linux kernel v3.1.0, and sometimes routing to a few IP addresses
> does not work. What seems to happen is that instead of sending the packet to
> the gateway, the kernel treats the destination address as local, and tries to
> gets its MAC address via ARP.
>
> For example, now my current IP address is 172.16.1.104/24, the gateway is
> 172.16.1.254:
>
> |# ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:1B:63:97:FC:DC
> inet addr:172.16.1.104 Bcast:172.16.1.255 Mask:255.255.255.0
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:230772 errors:0 dropped:0 overruns:0 frame:0
> TX packets:171013 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:191879370 (182.9 Mb) TX bytes:47173253 (44.9 Mb)
> Interrupt:17
>
> # route -n
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use Iface
> 0.0.0.0 172.16.1.254 0.0.0.0 UG 0 0 0 eth0
> 172.16.1.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0
> |
>
> I can ping a few addresses, but not 172.16.0.59:
>
> |# ping -c1 172.16.1.254
> PING 172.16.1.254 (172.16.1.254) 56(84) bytes of data.
> 64 bytes from 172.16.1.254: icmp_seq=1 ttl=64 time=0.383 ms
>
> --- 172.16.1.254 ping statistics ---
> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
> rtt min/avg/max/mdev = 0.383/0.383/0.383/0.000 ms
> root@pozsybook:~# ping -c1 172.16.0.1
> PING 172.16.0.1 (172.16.0.1) 56(84) bytes of data.
> 64 bytes from 172.16.0.1: icmp_seq=1 ttl=63 time=5.54 ms
>
> --- 172.16.0.1 ping statistics ---
> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
> rtt min/avg/max/mdev = 5.545/5.545/5.545/0.000 ms
> root@pozsybook:~# ping -c1 172.16.0.2
> PING 172.16.0.2 (172.16.0.2) 56(84) bytes of data.
> 64 bytes from 172.16.0.2: icmp_seq=1 ttl=62 time=7.92 ms
>
> --- 172.16.0.2 ping statistics ---
> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
> rtt min/avg/max/mdev = 7.925/7.925/7.925/0.000 ms
> root@pozsybook:~# ping -c1 172.16.0.59
> PING 172.16.0.59 (172.16.0.59) 56(84) bytes of data.
> From 172.16.1.104 icmp_seq=1 Destination Host Unreachable
>
> --- 172.16.0.59 ping statistics ---
> 1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms
> |
>
> When trying to ping 172.16.0.59, I can see in tcpdump that an ARP req was
> sent:
>
> |# tcpdump -n -i eth0|grep ARP
> tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
> listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
> 15:25:16.671217 ARP, Request who-has 172.16.0.59 tell 172.16.1.104, length 28
> |
>
> and /proc/net/arp has an incomplete entry for 172.16.0.59:
>
> |# grep 172.16.0.59 /proc/net/arp
>
> 172.16.0.59 0x1 0x0 00:00:00:00:00:00 * eth0
> |
>
> Please note, that 172.16.0.59 /is/ accessible from this LAN from other
> computers.
>
>
> Does anyone have any idea of what's going on? Thanks,
>
>
> Balazs Pozsar
>
> ps: I think it is related to this one: https://lkml.org/lkml/2011/11/16/292
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
>
--
Three may keep a secret, if two of them are dead.
- Ben F.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: routing bug?
2011-11-18 12:48 ` routing bug? Sven-Haegar Koch
@ 2011-11-18 13:09 ` Eric Dumazet
2011-11-18 13:23 ` Pozsár Balázs
0 siblings, 1 reply; 6+ messages in thread
From: Eric Dumazet @ 2011-11-18 13:09 UTC (permalink / raw)
To: Sven-Haegar Koch
Cc: Pozsár Balázs, Linux-Kernel-Mailinglist,
Tamási János, netdev
Le vendredi 18 novembre 2011 à 13:48 +0100, Sven-Haegar Koch a écrit :
> Added netdev list to CC:, there you should have a higher chance of a
> usefull answer.
>
> On Fri, 18 Nov 2011, Pozsár Balázs wrote:
>
> > Hi all,
> >
> > I have been struggling with this not easily reproducible issue since a while.
> > I am using linux kernel v3.1.0, and sometimes routing to a few IP addresses
> > does not work. What seems to happen is that instead of sending the packet to
> > the gateway, the kernel treats the destination address as local, and tries to
> > gets its MAC address via ARP.
> >
> > For example, now my current IP address is 172.16.1.104/24, the gateway is
> > 172.16.1.254:
> >
> > |# ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:1B:63:97:FC:DC
> > inet addr:172.16.1.104 Bcast:172.16.1.255 Mask:255.255.255.0
> > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> > RX packets:230772 errors:0 dropped:0 overruns:0 frame:0
> > TX packets:171013 errors:0 dropped:0 overruns:0 carrier:0
> > collisions:0 txqueuelen:1000
> > RX bytes:191879370 (182.9 Mb) TX bytes:47173253 (44.9 Mb)
> > Interrupt:17
> >
> > # route -n
> > Kernel IP routing table
> > Destination Gateway Genmask Flags Metric Ref Use Iface
> > 0.0.0.0 172.16.1.254 0.0.0.0 UG 0 0 0 eth0
> > 172.16.1.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0
> > |
> >
> > I can ping a few addresses, but not 172.16.0.59:
> >
> > |# ping -c1 172.16.1.254
> > PING 172.16.1.254 (172.16.1.254) 56(84) bytes of data.
> > 64 bytes from 172.16.1.254: icmp_seq=1 ttl=64 time=0.383 ms
> >
> > --- 172.16.1.254 ping statistics ---
> > 1 packets transmitted, 1 received, 0% packet loss, time 0ms
> > rtt min/avg/max/mdev = 0.383/0.383/0.383/0.000 ms
> > root@pozsybook:~# ping -c1 172.16.0.1
> > PING 172.16.0.1 (172.16.0.1) 56(84) bytes of data.
> > 64 bytes from 172.16.0.1: icmp_seq=1 ttl=63 time=5.54 ms
> >
> > --- 172.16.0.1 ping statistics ---
> > 1 packets transmitted, 1 received, 0% packet loss, time 0ms
> > rtt min/avg/max/mdev = 5.545/5.545/5.545/0.000 ms
> > root@pozsybook:~# ping -c1 172.16.0.2
> > PING 172.16.0.2 (172.16.0.2) 56(84) bytes of data.
> > 64 bytes from 172.16.0.2: icmp_seq=1 ttl=62 time=7.92 ms
> >
> > --- 172.16.0.2 ping statistics ---
> > 1 packets transmitted, 1 received, 0% packet loss, time 0ms
> > rtt min/avg/max/mdev = 7.925/7.925/7.925/0.000 ms
> > root@pozsybook:~# ping -c1 172.16.0.59
> > PING 172.16.0.59 (172.16.0.59) 56(84) bytes of data.
> > From 172.16.1.104 icmp_seq=1 Destination Host Unreachable
> >
> > --- 172.16.0.59 ping statistics ---
> > 1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms
> > |
> >
> > When trying to ping 172.16.0.59, I can see in tcpdump that an ARP req was
> > sent:
> >
> > |# tcpdump -n -i eth0|grep ARP
> > tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
> > listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
> > 15:25:16.671217 ARP, Request who-has 172.16.0.59 tell 172.16.1.104, length 28
> > |
> >
> > and /proc/net/arp has an incomplete entry for 172.16.0.59:
> >
> > |# grep 172.16.0.59 /proc/net/arp
> >
> > 172.16.0.59 0x1 0x0 00:00:00:00:00:00 * eth0
> > |
> >
> > Please note, that 172.16.0.59 /is/ accessible from this LAN from other
> > computers.
> >
> >
> > Does anyone have any idea of what's going on? Thanks,
> >
> >
> > Balazs Pozsar
> >
> > ps: I think it is related to this one: https://lkml.org/lkml/2011/11/16/292
> >
> > --
Could you send us result of :
ip route get 172.16.0.59
ip route list cache match 172.16.0.59
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: routing bug?
2011-11-18 13:09 ` Eric Dumazet
@ 2011-11-18 13:23 ` Pozsár Balázs
2011-11-18 13:33 ` Eric Dumazet
0 siblings, 1 reply; 6+ messages in thread
From: Pozsár Balázs @ 2011-11-18 13:23 UTC (permalink / raw)
To: Eric Dumazet
Cc: Sven-Haegar Koch, Linux-Kernel-Mailinglist,
Tamási János, netdev
On 2011-11-18 14:09, Eric Dumazet wrote:
> Le vendredi 18 novembre 2011 à 13:48 +0100, Sven-Haegar Koch a écrit :
>
>> Added netdev list to CC:, there you should have a higher chance of a
>> usefull answer.
>>
>> On Fri, 18 Nov 2011, Pozsár Balázs wrote:
>>
>>
>>> Hi all,
>>>
>>> I have been struggling with this not easily reproducible issue since a while.
>>> I am using linux kernel v3.1.0, and sometimes routing to a few IP addresses
>>> does not work. What seems to happen is that instead of sending the packet to
>>> the gateway, the kernel treats the destination address as local, and tries to
>>> gets its MAC address via ARP.
>>>
>>> For example, now my current IP address is 172.16.1.104/24, the gateway is
>>> 172.16.1.254:
>>>
>>> |# ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:1B:63:97:FC:DC
>>> inet addr:172.16.1.104 Bcast:172.16.1.255 Mask:255.255.255.0
>>> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
>>> RX packets:230772 errors:0 dropped:0 overruns:0 frame:0
>>> TX packets:171013 errors:0 dropped:0 overruns:0 carrier:0
>>> collisions:0 txqueuelen:1000
>>> RX bytes:191879370 (182.9 Mb) TX bytes:47173253 (44.9 Mb)
>>> Interrupt:17
>>>
>>> # route -n
>>> Kernel IP routing table
>>> Destination Gateway Genmask Flags Metric Ref Use Iface
>>> 0.0.0.0 172.16.1.254 0.0.0.0 UG 0 0 0 eth0
>>> 172.16.1.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0
>>> |
>>>
>>> I can ping a few addresses, but not 172.16.0.59:
>>>
>>> |# ping -c1 172.16.1.254
>>> PING 172.16.1.254 (172.16.1.254) 56(84) bytes of data.
>>> 64 bytes from 172.16.1.254: icmp_seq=1 ttl=64 time=0.383 ms
>>>
>>> --- 172.16.1.254 ping statistics ---
>>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
>>> rtt min/avg/max/mdev = 0.383/0.383/0.383/0.000 ms
>>> root@pozsybook:~# ping -c1 172.16.0.1
>>> PING 172.16.0.1 (172.16.0.1) 56(84) bytes of data.
>>> 64 bytes from 172.16.0.1: icmp_seq=1 ttl=63 time=5.54 ms
>>>
>>> --- 172.16.0.1 ping statistics ---
>>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
>>> rtt min/avg/max/mdev = 5.545/5.545/5.545/0.000 ms
>>> root@pozsybook:~# ping -c1 172.16.0.2
>>> PING 172.16.0.2 (172.16.0.2) 56(84) bytes of data.
>>> 64 bytes from 172.16.0.2: icmp_seq=1 ttl=62 time=7.92 ms
>>>
>>> --- 172.16.0.2 ping statistics ---
>>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
>>> rtt min/avg/max/mdev = 7.925/7.925/7.925/0.000 ms
>>> root@pozsybook:~# ping -c1 172.16.0.59
>>> PING 172.16.0.59 (172.16.0.59) 56(84) bytes of data.
>>> From 172.16.1.104 icmp_seq=1 Destination Host Unreachable
>>>
>>> --- 172.16.0.59 ping statistics ---
>>> 1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms
>>> |
>>>
>>> When trying to ping 172.16.0.59, I can see in tcpdump that an ARP req was
>>> sent:
>>>
>>> |# tcpdump -n -i eth0|grep ARP
>>> tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
>>> listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
>>> 15:25:16.671217 ARP, Request who-has 172.16.0.59 tell 172.16.1.104, length 28
>>> |
>>>
>>> and /proc/net/arp has an incomplete entry for 172.16.0.59:
>>>
>>> |# grep 172.16.0.59 /proc/net/arp
>>>
>>> 172.16.0.59 0x1 0x0 00:00:00:00:00:00 * eth0
>>> |
>>>
>>> Please note, that 172.16.0.59 /is/ accessible from this LAN from other
>>> computers.
>>>
>>>
>>> Does anyone have any idea of what's going on? Thanks,
>>>
>>>
>>> Balazs Pozsar
>>>
>>> ps: I think it is related to this one: https://lkml.org/lkml/2011/11/16/292
>>>
>>> --
>>>
> Could you send us result of :
>
> ip route get 172.16.0.59
> ip route list cache match 172.16.0.59
>
I did not tell you in my first mail, that some times different hosts are
reachable and unreachable. I will try to not confuse you :)
As of now, 172.16.0.59 is OK, and 172.16.0.37 is NOT OK.
Also, 172.16.0.64 is OK now, and 172.16.0.42 is NOT OK now.
The two commands you have requested give the following output for these
IP addresses:
These are OK:
# ip route get 172.16.0.64
172.16.0.64 via 172.16.1.254 dev eth0 src 172.16.1.22
cache
# ip route get 172.16.0.59
172.16.0.59 via 172.16.1.254 dev eth0 src 172.16.1.22
cache
These are NOT OK:
# ip route get 172.16.0.37
172.16.0.37 dev eth0 src 172.16.1.22
cache <redirected> ipid 0x97a4
# ip route get 172.16.0.42
172.16.0.42 dev eth0 src 172.16.1.22
cache <redirected> ipid 0x0d21
These are OK:
# ip route list cache match 172.16.0.59
172.16.0.59 via 172.16.1.254 dev eth0 src 172.16.1.22
cache
# ip route list cache match 172.16.0.64
172.16.0.64 via 172.16.1.254 dev eth0 src 172.16.1.22
cache
These are NOT OK:
# ip route list cache match 172.16.0.37
172.16.0.37 dev eth0 src 172.16.1.22
cache <redirected> ipid 0x97a4
172.16.0.37 from 172.16.1.22 dev eth0
cache <redirected> ipid 0x97a4
172.16.0.37 from 172.16.1.22 dev eth0
cache <redirected> ipid 0x97a4
# ip route list cache match 172.16.0.42
172.16.0.42 dev eth0 src 172.16.1.22
cache <redirected> ipid 0x0d21
172.16.0.42 from 172.16.1.22 dev eth0
cache <redirected> ipid 0x0d21
How can I fix this?
Thanks!
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: routing bug?
2011-11-18 13:23 ` Pozsár Balázs
@ 2011-11-18 13:33 ` Eric Dumazet
2011-11-18 13:38 ` Pozsár Balázs
0 siblings, 1 reply; 6+ messages in thread
From: Eric Dumazet @ 2011-11-18 13:33 UTC (permalink / raw)
To: Pozsár Balázs
Cc: Sven-Haegar Koch, Linux-Kernel-Mailinglist,
Tamási János, netdev
Le vendredi 18 novembre 2011 à 14:23 +0100, Pozsár Balázs a écrit :
> On 2011-11-18 14:09, Eric Dumazet wrote:
> > Le vendredi 18 novembre 2011 à 13:48 +0100, Sven-Haegar Koch a écrit :
> >
> >> Added netdev list to CC:, there you should have a higher chance of a
> >> usefull answer.
> >>
> >> On Fri, 18 Nov 2011, Pozsár Balázs wrote:
> >>
> >>
> >>> Hi all,
> >>>
> >>> I have been struggling with this not easily reproducible issue since a while.
> >>> I am using linux kernel v3.1.0, and sometimes routing to a few IP addresses
> >>> does not work. What seems to happen is that instead of sending the packet to
> >>> the gateway, the kernel treats the destination address as local, and tries to
> >>> gets its MAC address via ARP.
> >>>
> >>> For example, now my current IP address is 172.16.1.104/24, the gateway is
> >>> 172.16.1.254:
> >>>
> >>> |# ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:1B:63:97:FC:DC
> >>> inet addr:172.16.1.104 Bcast:172.16.1.255 Mask:255.255.255.0
> >>> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> >>> RX packets:230772 errors:0 dropped:0 overruns:0 frame:0
> >>> TX packets:171013 errors:0 dropped:0 overruns:0 carrier:0
> >>> collisions:0 txqueuelen:1000
> >>> RX bytes:191879370 (182.9 Mb) TX bytes:47173253 (44.9 Mb)
> >>> Interrupt:17
> >>>
> >>> # route -n
> >>> Kernel IP routing table
> >>> Destination Gateway Genmask Flags Metric Ref Use Iface
> >>> 0.0.0.0 172.16.1.254 0.0.0.0 UG 0 0 0 eth0
> >>> 172.16.1.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0
> >>> |
> >>>
> >>> I can ping a few addresses, but not 172.16.0.59:
> >>>
> >>> |# ping -c1 172.16.1.254
> >>> PING 172.16.1.254 (172.16.1.254) 56(84) bytes of data.
> >>> 64 bytes from 172.16.1.254: icmp_seq=1 ttl=64 time=0.383 ms
> >>>
> >>> --- 172.16.1.254 ping statistics ---
> >>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
> >>> rtt min/avg/max/mdev = 0.383/0.383/0.383/0.000 ms
> >>> root@pozsybook:~# ping -c1 172.16.0.1
> >>> PING 172.16.0.1 (172.16.0.1) 56(84) bytes of data.
> >>> 64 bytes from 172.16.0.1: icmp_seq=1 ttl=63 time=5.54 ms
> >>>
> >>> --- 172.16.0.1 ping statistics ---
> >>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
> >>> rtt min/avg/max/mdev = 5.545/5.545/5.545/0.000 ms
> >>> root@pozsybook:~# ping -c1 172.16.0.2
> >>> PING 172.16.0.2 (172.16.0.2) 56(84) bytes of data.
> >>> 64 bytes from 172.16.0.2: icmp_seq=1 ttl=62 time=7.92 ms
> >>>
> >>> --- 172.16.0.2 ping statistics ---
> >>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
> >>> rtt min/avg/max/mdev = 7.925/7.925/7.925/0.000 ms
> >>> root@pozsybook:~# ping -c1 172.16.0.59
> >>> PING 172.16.0.59 (172.16.0.59) 56(84) bytes of data.
> >>> From 172.16.1.104 icmp_seq=1 Destination Host Unreachable
> >>>
> >>> --- 172.16.0.59 ping statistics ---
> >>> 1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms
> >>> |
> >>>
> >>> When trying to ping 172.16.0.59, I can see in tcpdump that an ARP req was
> >>> sent:
> >>>
> >>> |# tcpdump -n -i eth0|grep ARP
> >>> tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
> >>> listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
> >>> 15:25:16.671217 ARP, Request who-has 172.16.0.59 tell 172.16.1.104, length 28
> >>> |
> >>>
> >>> and /proc/net/arp has an incomplete entry for 172.16.0.59:
> >>>
> >>> |# grep 172.16.0.59 /proc/net/arp
> >>>
> >>> 172.16.0.59 0x1 0x0 00:00:00:00:00:00 * eth0
> >>> |
> >>>
> >>> Please note, that 172.16.0.59 /is/ accessible from this LAN from other
> >>> computers.
> >>>
> >>>
> >>> Does anyone have any idea of what's going on? Thanks,
> >>>
> >>>
> >>> Balazs Pozsar
> >>>
> >>> ps: I think it is related to this one: https://lkml.org/lkml/2011/11/16/292
> >>>
> >>> --
> >>>
> > Could you send us result of :
> >
> > ip route get 172.16.0.59
> > ip route list cache match 172.16.0.59
> >
>
> I did not tell you in my first mail, that some times different hosts are
> reachable and unreachable. I will try to not confuse you :)
> As of now, 172.16.0.59 is OK, and 172.16.0.37 is NOT OK.
> Also, 172.16.0.64 is OK now, and 172.16.0.42 is NOT OK now.
>
> The two commands you have requested give the following output for these
> IP addresses:
>
> These are OK:
>
> # ip route get 172.16.0.64
> 172.16.0.64 via 172.16.1.254 dev eth0 src 172.16.1.22
> cache
> # ip route get 172.16.0.59
> 172.16.0.59 via 172.16.1.254 dev eth0 src 172.16.1.22
> cache
>
> These are NOT OK:
>
> # ip route get 172.16.0.37
> 172.16.0.37 dev eth0 src 172.16.1.22
> cache <redirected> ipid 0x97a4
> # ip route get 172.16.0.42
> 172.16.0.42 dev eth0 src 172.16.1.22
> cache <redirected> ipid 0x0d21
>
> These are OK:
>
> # ip route list cache match 172.16.0.59
> 172.16.0.59 via 172.16.1.254 dev eth0 src 172.16.1.22
> cache
> # ip route list cache match 172.16.0.64
> 172.16.0.64 via 172.16.1.254 dev eth0 src 172.16.1.22
> cache
>
> These are NOT OK:
>
> # ip route list cache match 172.16.0.37
> 172.16.0.37 dev eth0 src 172.16.1.22
> cache <redirected> ipid 0x97a4
> 172.16.0.37 from 172.16.1.22 dev eth0
> cache <redirected> ipid 0x97a4
> 172.16.0.37 from 172.16.1.22 dev eth0
> cache <redirected> ipid 0x97a4
> # ip route list cache match 172.16.0.42
> 172.16.0.42 dev eth0 src 172.16.1.22
> cache <redirected> ipid 0x0d21
> 172.16.0.42 from 172.16.1.22 dev eth0
> cache <redirected> ipid 0x0d21
>
>
> How can I fix this?
>
> Thanks!
We are working on it (see threads in netdev)
You can in the meantime
echo 0 >/proc/sys/net/ipv4/conf/eth0/accept_redirects
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: routing bug?
2011-11-18 13:33 ` Eric Dumazet
@ 2011-11-18 13:38 ` Pozsár Balázs
2011-11-18 13:54 ` Eric Dumazet
0 siblings, 1 reply; 6+ messages in thread
From: Pozsár Balázs @ 2011-11-18 13:38 UTC (permalink / raw)
To: Eric Dumazet
Cc: Sven-Haegar Koch, Linux-Kernel-Mailinglist,
Tamási János, netdev
On 2011-11-18 14:33, Eric Dumazet wrote:
> Le vendredi 18 novembre 2011 à 14:23 +0100, Pozsár Balázs a écrit :
>
>> On 2011-11-18 14:09, Eric Dumazet wrote:
>>
>>> Le vendredi 18 novembre 2011 à 13:48 +0100, Sven-Haegar Koch a écrit :
>>>
>>>
>>>> Added netdev list to CC:, there you should have a higher chance of a
>>>> usefull answer.
>>>>
>>>> On Fri, 18 Nov 2011, Pozsár Balázs wrote:
>>>>
>>>>
>>>>
>>>>> Hi all,
>>>>>
>>>>> I have been struggling with this not easily reproducible issue since a while.
>>>>> I am using linux kernel v3.1.0, and sometimes routing to a few IP addresses
>>>>> does not work. What seems to happen is that instead of sending the packet to
>>>>> the gateway, the kernel treats the destination address as local, and tries to
>>>>> gets its MAC address via ARP.
>>>>>
>>>>> For example, now my current IP address is 172.16.1.104/24, the gateway is
>>>>> 172.16.1.254:
>>>>>
>>>>> |# ifconfig eth0 eth0 Link encap:Ethernet HWaddr 00:1B:63:97:FC:DC
>>>>> inet addr:172.16.1.104 Bcast:172.16.1.255 Mask:255.255.255.0
>>>>> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
>>>>> RX packets:230772 errors:0 dropped:0 overruns:0 frame:0
>>>>> TX packets:171013 errors:0 dropped:0 overruns:0 carrier:0
>>>>> collisions:0 txqueuelen:1000
>>>>> RX bytes:191879370 (182.9 Mb) TX bytes:47173253 (44.9 Mb)
>>>>> Interrupt:17
>>>>>
>>>>> # route -n
>>>>> Kernel IP routing table
>>>>> Destination Gateway Genmask Flags Metric Ref Use Iface
>>>>> 0.0.0.0 172.16.1.254 0.0.0.0 UG 0 0 0 eth0
>>>>> 172.16.1.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0
>>>>> |
>>>>>
>>>>> I can ping a few addresses, but not 172.16.0.59:
>>>>>
>>>>> |# ping -c1 172.16.1.254
>>>>> PING 172.16.1.254 (172.16.1.254) 56(84) bytes of data.
>>>>> 64 bytes from 172.16.1.254: icmp_seq=1 ttl=64 time=0.383 ms
>>>>>
>>>>> --- 172.16.1.254 ping statistics ---
>>>>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
>>>>> rtt min/avg/max/mdev = 0.383/0.383/0.383/0.000 ms
>>>>> root@pozsybook:~# ping -c1 172.16.0.1
>>>>> PING 172.16.0.1 (172.16.0.1) 56(84) bytes of data.
>>>>> 64 bytes from 172.16.0.1: icmp_seq=1 ttl=63 time=5.54 ms
>>>>>
>>>>> --- 172.16.0.1 ping statistics ---
>>>>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
>>>>> rtt min/avg/max/mdev = 5.545/5.545/5.545/0.000 ms
>>>>> root@pozsybook:~# ping -c1 172.16.0.2
>>>>> PING 172.16.0.2 (172.16.0.2) 56(84) bytes of data.
>>>>> 64 bytes from 172.16.0.2: icmp_seq=1 ttl=62 time=7.92 ms
>>>>>
>>>>> --- 172.16.0.2 ping statistics ---
>>>>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
>>>>> rtt min/avg/max/mdev = 7.925/7.925/7.925/0.000 ms
>>>>> root@pozsybook:~# ping -c1 172.16.0.59
>>>>> PING 172.16.0.59 (172.16.0.59) 56(84) bytes of data.
>>>>> From 172.16.1.104 icmp_seq=1 Destination Host Unreachable
>>>>>
>>>>> --- 172.16.0.59 ping statistics ---
>>>>> 1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms
>>>>> |
>>>>>
>>>>> When trying to ping 172.16.0.59, I can see in tcpdump that an ARP req was
>>>>> sent:
>>>>>
>>>>> |# tcpdump -n -i eth0|grep ARP
>>>>> tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
>>>>> listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
>>>>> 15:25:16.671217 ARP, Request who-has 172.16.0.59 tell 172.16.1.104, length 28
>>>>> |
>>>>>
>>>>> and /proc/net/arp has an incomplete entry for 172.16.0.59:
>>>>>
>>>>> |# grep 172.16.0.59 /proc/net/arp
>>>>>
>>>>> 172.16.0.59 0x1 0x0 00:00:00:00:00:00 * eth0
>>>>> |
>>>>>
>>>>> Please note, that 172.16.0.59 /is/ accessible from this LAN from other
>>>>> computers.
>>>>>
>>>>>
>>>>> Does anyone have any idea of what's going on? Thanks,
>>>>>
>>>>>
>>>>> Balazs Pozsar
>>>>>
>>>>> ps: I think it is related to this one: https://lkml.org/lkml/2011/11/16/292
>>>>>
>>>>> --
>>>>>
>>>>>
>>> Could you send us result of :
>>>
>>> ip route get 172.16.0.59
>>> ip route list cache match 172.16.0.59
>>>
>>>
>> I did not tell you in my first mail, that some times different hosts are
>> reachable and unreachable. I will try to not confuse you :)
>> As of now, 172.16.0.59 is OK, and 172.16.0.37 is NOT OK.
>> Also, 172.16.0.64 is OK now, and 172.16.0.42 is NOT OK now.
>>
>> The two commands you have requested give the following output for these
>> IP addresses:
>>
>> These are OK:
>>
>> # ip route get 172.16.0.64
>> 172.16.0.64 via 172.16.1.254 dev eth0 src 172.16.1.22
>> cache
>> # ip route get 172.16.0.59
>> 172.16.0.59 via 172.16.1.254 dev eth0 src 172.16.1.22
>> cache
>>
>> These are NOT OK:
>>
>> # ip route get 172.16.0.37
>> 172.16.0.37 dev eth0 src 172.16.1.22
>> cache<redirected> ipid 0x97a4
>> # ip route get 172.16.0.42
>> 172.16.0.42 dev eth0 src 172.16.1.22
>> cache<redirected> ipid 0x0d21
>>
>> These are OK:
>>
>> # ip route list cache match 172.16.0.59
>> 172.16.0.59 via 172.16.1.254 dev eth0 src 172.16.1.22
>> cache
>> # ip route list cache match 172.16.0.64
>> 172.16.0.64 via 172.16.1.254 dev eth0 src 172.16.1.22
>> cache
>>
>> These are NOT OK:
>>
>> # ip route list cache match 172.16.0.37
>> 172.16.0.37 dev eth0 src 172.16.1.22
>> cache<redirected> ipid 0x97a4
>> 172.16.0.37 from 172.16.1.22 dev eth0
>> cache<redirected> ipid 0x97a4
>> 172.16.0.37 from 172.16.1.22 dev eth0
>> cache<redirected> ipid 0x97a4
>> # ip route list cache match 172.16.0.42
>> 172.16.0.42 dev eth0 src 172.16.1.22
>> cache<redirected> ipid 0x0d21
>> 172.16.0.42 from 172.16.1.22 dev eth0
>> cache<redirected> ipid 0x0d21
>>
>>
>> How can I fix this?
>>
>> Thanks!
>>
> We are working on it (see threads in netdev)
>
> You can in the meantime
>
> echo 0>/proc/sys/net/ipv4/conf/eth0/accept_redirects
>
Unfortunately it does not solve the problem for me, I have have these
"cache <redirected>" entries even after that echo command.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: routing bug?
2011-11-18 13:38 ` Pozsár Balázs
@ 2011-11-18 13:54 ` Eric Dumazet
0 siblings, 0 replies; 6+ messages in thread
From: Eric Dumazet @ 2011-11-18 13:54 UTC (permalink / raw)
To: Pozsár Balázs
Cc: Sven-Haegar Koch, Linux-Kernel-Mailinglist,
Tamási János, netdev
Le vendredi 18 novembre 2011 à 14:38 +0100, Pozsár Balázs a écrit :
> Unfortunately it does not solve the problem for me, I have have these
> "cache <redirected>" entries even after that echo command.
>
Its a problem with a cached value.
You must reboot to flush it.
It was already discussed yesterday on netdev.
^ permalink raw reply [flat|nested] 6+ messages in thread
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2011-11-18 12:48 ` routing bug? Sven-Haegar Koch
2011-11-18 13:09 ` Eric Dumazet
2011-11-18 13:23 ` Pozsár Balázs
2011-11-18 13:33 ` Eric Dumazet
2011-11-18 13:38 ` Pozsár Balázs
2011-11-18 13:54 ` Eric Dumazet
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