Routing and ARP Problem - HELP

Hello Newsgroup,

I could not find any solution for my problem, and hope to fine it here.

Some specifications:
Genttoo Linux (2.6.8.1) running on HP ProLiant DL 360 G4 2x3.0 GHz
DualCore XEON
1 x 2 Port OnBoard Mobo nic (tg3 module)
2 x 4 Port Intel Pro 1000 (So we have 10 eth Interfaces - from eth0 to
eth9)

My Problem was, that eth0 had answered to any ARP Request, which was
sent to eth1 - eth9 for example. So it answered every arp request for he
other Interfaces.

I followed these Steps at:
http://forums.gentoo.org/viewtopic.p...149737#2149737 and now my eth0
interface answers only to ARP Requests, which are explicity for itself.

But now, the other Interfaces do not function correctly. When I try to
ping eth1 for example, I see the ARP Request (tcpdump) on eth1 but eth1
does not answer the ARP REQUEST, so no IP connection gets established.

Can anyone please give me a hint? What is wrong here? Why do my other
eth Interfaces no more answer to ARP Requests? My eth0 - and only eth0 -
still function as it should.

Thanks in Advance!

Regards,
Adem Sen

Adem Sen wrote:
> Hello Newsgroup,
>
> I could not find any solution for my problem, and hope to fine it here.
>
> Some specifications:
> Genttoo Linux (2.6.8.1) running on HP ProLiant DL 360 G4 2x3.0 GHz
> DualCore XEON
> 1 x 2 Port OnBoard Mobo nic (tg3 module)
> 2 x 4 Port Intel Pro 1000 (So we have 10 eth Interfaces - from eth0 to
> eth9)
>
> My Problem was, that eth0 had answered to any ARP Request, which was
> sent to eth1 - eth9 for example. So it answered every arp request for he
> other Interfaces.
>
> I followed these Steps at:
> http://forums.gentoo.org/viewtopic.p...149737#2149737 and now my eth0
> interface answers only to ARP Requests, which are explicity for itself.
>
> But now, the other Interfaces do not function correctly. When I try to
> ping eth1 for example, I see the ARP Request (tcpdump) on eth1 but eth1
> does not answer the ARP REQUEST, so no IP connection gets established.
>
> Can anyone please give me a hint? What is wrong here? Why do my other
> eth Interfaces no more answer to ARP Requests? My eth0 - and only eth0 -
> still function as it should.
>

Please post the output of the commands (as root):

ifconfig -a
route -n

so your setup can be verified.

--

Tauno Voipio
tauno voipio (at) iki fi

Adem Sen wrote:
> Hello Newsgroup,
>
> I could not find any solution for my problem, and hope to fine it
here.
>
> Some specifications:
> Genttoo Linux (2.6.8.1) running on HP ProLiant DL 360 G4 2x3.0 GHz
> DualCore XEON
> 1 x 2 Port OnBoard Mobo nic (tg3 module)
> 2 x 4 Port Intel Pro 1000 (So we have 10 eth Interfaces - from eth0
to
> eth9)
>
> My Problem was, that eth0 had answered to any ARP Request, which was
> sent to eth1 - eth9 for example. So it answered every arp request for
he
> other Interfaces.

Default Linux behavior.

> I followed these Steps at:

Which steps and which settings did you use?

> http://forums.gentoo.org/viewtopic.p...149737#2149737 and now my
eth0
> interface answers only to ARP Requests, which are explicity for
itself.
>
> But now, the other Interfaces do not function correctly. When I try
to
> ping eth1 for example, I see the ARP Request (tcpdump) on eth1 but
eth1
> does not answer the ARP REQUEST, so no IP connection gets
established.

You will always need to flush arp caches whenever you change settings
that effect arp reply/request changes. This will force new arp
requests. Arping can sometimes be used to "force" new arp cache
entries.

> Can anyone please give me a hint? What is wrong here? Why do my other

> eth Interfaces no more answer to ARP Requests? My eth0 - and only
eth0 -
> still function as it should.

You could have a number of issues here, but hopefully the reworked 2.6
kernel deals with some of them. I don't have ready access to a 2.6
kernel machine so can't say what peculiar problems may lie there.

With arp_filter=1 _and_ with proper route table entries you may get
your needed behavior.

>From your posting to gentoo:
"The problem is, that our current design will for sure not work this
way since we are in same subnet and i can only set one default gateway
over one nic."

It sounds like your hoping to direct some nics/IPs to use a different
(non-default) gateway. There is no problem with having multiple
gateways. You can (normally) only have a single _default_ gateway. To
use more than one gateway, of course, multiple gateways must be
available on the subnet.

Even with a single gateway, the other nic/IPs will probably need a
distinct route table entry with an explict gateway entry (ie., don't
expect them to simply use the default GW).

If this still does not provide needed behavior, you may have to use
multiple routing tables. It's not clear if this will be _necessary_
for your needs, but it may be needed or well advised _if_ you can get
some cooperation from whoever controls the gateway(s) router(s). Using
the ip tools and policy routing you can effectively run multiple IP
nets on the same physical (ethernet) network.

You may find these useful:
http://ipsysctl-tutorial.frozentux.n...-tutorial.html
http://linux-ip.net/html/
http://linux-ip.net/gl/ip-cref/ < ip tools reference
http://www.policyrouting.org/PolicyR...NLINE/TOC.html

hth,
prg

In article <Ob0Xd.235$(E-Mail Removed)>,
(E-Mail Removed)lid says...
> Adem Sen wrote:
> > Hello Newsgroup,
> >
> > I could not find any solution for my problem, and hope to fine it here.
> >
> > Some specifications:
> > Genttoo Linux (2.6.8.1) running on HP ProLiant DL 360 G4 2x3.0 GHz
> > DualCore XEON
> > 1 x 2 Port OnBoard Mobo nic (tg3 module)
> > 2 x 4 Port Intel Pro 1000 (So we have 10 eth Interfaces - from eth0 to
> > eth9)
> >
> > My Problem was, that eth0 had answered to any ARP Request, which was
> > sent to eth1 - eth9 for example. So it answered every arp request for he
> > other Interfaces.
> >
> > I followed these Steps at:
> > http://forums.gentoo.org/viewtopic.p...149737#2149737 and now my eth0
> > interface answers only to ARP Requests, which are explicity for itself.
> >
> > But now, the other Interfaces do not function correctly. When I try to
> > ping eth1 for example, I see the ARP Request (tcpdump) on eth1 but eth1
> > does not answer the ARP REQUEST, so no IP connection gets established.
> >
> > Can anyone please give me a hint? What is wrong here? Why do my other
> > eth Interfaces no more answer to ARP Requests? My eth0 - and only eth0 -
> > still function as it should.
> >
>
> Please post the output of the commands (as root):
>
> ifconfig -a
> route -n
> so your setup can be verified.

Thanks, hee is "route -n":

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.72.0.0 0.0.0.0 255.255.248.0 U 0 0 0 eth0
10.72.0.0 0.0.0.0 255.255.248.0 U 0 0 0 eth1
10.72.0.0 0.0.0.0 255.255.248.0 U 0 0 0 eth2
127.0.0.0 127.0.0.1 255.0.0.0 UG 0 0 0 lo
0.0.0.0 10.72.0.254 0.0.0.0 UG 0 0 0 eth0

And here is "ifconfig -a":

eth0 Link encap:Ethernet HWaddr 00:11:85:C4:06:0B
inet addr:10.72.0.135 Bcast:10.72.0.255 Mask:255.255.248.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:5769901 errors:0 dropped:0 overruns:0 frame:0
TX packets:5329748 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:923114800 (880.3 Mb) TX bytes:604379903 (576.3 Mb)
Interrupt:5

eth1 Link encap:Ethernet HWaddr 00:11:85:C4:06:0A
inet addr:10.72.0.136 Bcast:10.72.0.255 Mask:255.255.248.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:5

eth2 Link encap:Ethernet HWaddr 00:04:23:B1:89:C8
inet addr:10.72.0.137 Bcast:10.72.0.255 Mask:255.255.248.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:354741 errors:0 dropped:0 overruns:0 frame:0
TX packets:1017 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:23276340 (22.1 Mb) TX bytes:65088 (63.5 Kb)
Base address:0x5000 Memory:fdee0000-fdf00000

eth3 Link encap:Ethernet HWaddr 00:04:23:B1:89:C9
inet addr:10.72.0.138 Bcast:10.72.0.255 Mask:255.255.255.255
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Base address:0x5040 Memory:fdec0000-fdee0000

eth4 Link encap:Ethernet HWaddr 00:04:23:B1:89:CA
inet addr:10.72.0.139 Bcast:10.72.0.255 Mask:255.255.255.255
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Base address:0x5080 Memory:fdea0000-fdec0000

eth5 Link encap:Ethernet HWaddr 00:04:23:B1:89:CB
inet addr:10.72.0.140 Bcast:10.72.0.255 Mask:255.255.255.255
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Base address:0x50c0 Memory:fde80000-fdea0000

eth6 Link encap:Ethernet HWaddr 00:04:23:B1:8A:24
inet addr:10.72.0.141 Bcast:10.72.0.255 Mask:255.255.255.255
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Base address:0x6000 Memory:fdfe0000-fe000000

eth7 Link encap:Ethernet HWaddr 00:04:23:B1:8A:25
inet addr:10.72.0.142 Bcast:10.72.0.255 Mask:255.255.255.255
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Base address:0x6040 Memory:fdfc0000-fdfe0000

eth8 Link encap:Ethernet HWaddr 00:04:23:B1:8A:26
inet addr:10.72.0.143 Bcast:10.72.0.255 Mask:255.255.255.255
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Base address:0x6080 Memory:fdfa0000-fdfc0000

eth9 Link encap:Ethernet HWaddr 00:04:23:B1:8A:27
inet addr:10.72.0.144 Bcast:10.72.0.255 Mask:255.255.255.255
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Base address:0x60c0 Memory:fdf80000-fdfa0000

imq0 Link encap:UNSPEC HWaddr 00-00-FF-FF-FF-FF-00-00-00-00-00-00-
00-00-00-00
NOARP MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:30
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

imq1 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-
00-00-00-00
NOARP MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:30
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:27578519 errors:0 dropped:0 overruns:0 frame:0
TX packets:27578519 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1275092683 (1216.0 Mb) TX bytes:1275092683 (1216.0
Mb)

teql0 Link encap:UNSPEC HWaddr 00-00-FF-00-00-00-00-00-00-00-00-00-
00-00-00-00
NOARP MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

Regards,
--
Adem Sen

Adem Sen wrote:

--- clip clip ---

> Thanks, here is "route -n":
>
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use Iface
> 10.72.0.0 0.0.0.0 255.255.248.0 U 0 0 0 eth0
> 10.72.0.0 0.0.0.0 255.255.248.0 U 0 0 0 eth1
> 10.72.0.0 0.0.0.0 255.255.248.0 U 0 0 0 eth2
> 127.0.0.0 127.0.0.1 255.0.0.0 UG 0 0 0 lo
> 0.0.0.0 10.72.0.254 0.0.0.0 UG 0 0 0 eth0

You have conflicting instructions for routing the network 10.72.0.0/21
(10.72.0.0 to 10.72.7.255): you require it to go via eth0, eth1 and
eth2. The poor router cannot decide.

> And here is "ifconfig -a":
>
> eth0 Link encap:Ethernet HWaddr 00:11:85:C4:06:0B
> inet addr:10.72.0.135 Bcast:10.72.0.255 Mask:255.255.248.0
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:5769901 errors:0 dropped:0 overruns:0 frame:0
> TX packets:5329748 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:923114800 (880.3 Mb) TX bytes:604379903 (576.3 Mb)
> Interrupt:5
>
> eth1 Link encap:Ethernet HWaddr 00:11:85:C4:06:0A
> inet addr:10.72.0.136 Bcast:10.72.0.255 Mask:255.255.248.0
> UP BROADCAST MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
> Interrupt:5
>
> eth2 Link encap:Ethernet HWaddr 00:04:23:B1:89:C8
> inet addr:10.72.0.137 Bcast:10.72.0.255 Mask:255.255.248.0
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:354741 errors:0 dropped:0 overruns:0 frame:0
> TX packets:1017 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:23276340 (22.1 Mb) TX bytes:65088 (63.5 Kb)
> Base address:0x5000 Memory:fdee0000-fdf00000
>
> eth3 Link encap:Ethernet HWaddr 00:04:23:B1:89:C9
> inet addr:10.72.0.138 Bcast:10.72.0.255 Mask:255.255.255.255
> UP BROADCAST MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
> Base address:0x5040 Memory:fdec0000-fdee0000
>
> eth4 Link encap:Ethernet HWaddr 00:04:23:B1:89:CA
> inet addr:10.72.0.139 Bcast:10.72.0.255 Mask:255.255.255.255
> UP BROADCAST MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
> Base address:0x5080 Memory:fdea0000-fdec0000
>
> eth5 Link encap:Ethernet HWaddr 00:04:23:B1:89:CB
> inet addr:10.72.0.140 Bcast:10.72.0.255 Mask:255.255.255.255
> UP BROADCAST MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
> Base address:0x50c0 Memory:fde80000-fdea0000
>
> eth6 Link encap:Ethernet HWaddr 00:04:23:B1:8A:24
> inet addr:10.72.0.141 Bcast:10.72.0.255 Mask:255.255.255.255
> UP BROADCAST MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
> Base address:0x6000 Memory:fdfe0000-fe000000
>
> eth7 Link encap:Ethernet HWaddr 00:04:23:B1:8A:25
> inet addr:10.72.0.142 Bcast:10.72.0.255 Mask:255.255.255.255
> UP BROADCAST MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
> Base address:0x6040 Memory:fdfc0000-fdfe0000
>
> eth8 Link encap:Ethernet HWaddr 00:04:23:B1:8A:26
> inet addr:10.72.0.143 Bcast:10.72.0.255 Mask:255.255.255.255
> UP BROADCAST MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
> Base address:0x6080 Memory:fdfa0000-fdfc0000
>
> eth9 Link encap:Ethernet HWaddr 00:04:23:B1:8A:27
> inet addr:10.72.0.144 Bcast:10.72.0.255 Mask:255.255.255.255
> UP BROADCAST MULTICAST MTU:1500 Metric:1
> RX packets:0 errors:0 dropped:0 overruns:0 frame:0
> TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
> Base address:0x60c0 Memory:fdf80000-fdfa0000
>
--- some clipped ---

You have all the interfaces in the same subnet. It will not work
without special route handling (dee Adv-Routing-HOWTO in LDP).

To work in a normal routing environment, see that the subnets
(seen under netmask) of the different interfaces do not overlap.

What are you trying to achieve?

If you want to replace a switch/hub with the multiple interfaces,
you should build a bridge interface of them, and assign the
subnet, netmask and route to it.

HTH

--

Tauno Voipio
tauno voipio (at) iki fi

In article <x12Xd.301$(E-Mail Removed)>,
(E-Mail Removed)lid says...

Thank you all for your help. The Problem was, that the switch was still
configured to set the server Port to the wrong V-LAN. Additionally there
was a conflict with the routes. I have solved this now and it works
great.

Regards,
Adem Sen

Thank you all for your help! The Problem was that the switch was
misconfigured and the interfaces of the server were in restricted V-
LAN's!

Regards,
--
Adem Sen

In article <(E-Mail Removed). com>,
(E-Mail Removed) says...

Hi,

I have Problems with ARP Request again.

eth0 = 10.72.0.135/21
eth1 = 10.72.0.136/21
and so on...until eth9 = 10.72.0.144/21

Now I PING all IPs from eth0 to eth9 from a Server in the same Subnet,
but always only eth0 does answer all ARP Requests, I saw this with
tcpdump.

I have set following Parameters in "/etc/sysctl.conf":

****
# Disables packet forwarding
#net.ipv4.ip_forward = 0
# Disables IP dynaddr
#net.ipv4.ip_dynaddr = 0
# Disable ECN
net.ipv4.tcp_ecn = 0
# Enables source route verification
#net.ipv4.conf.default.rp_filter = 1
# Disables the magic-sysrq key
#kernel.sysrq = 0
#net.ipv4.conf.all.arp_ignore = 1
#net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.all.arp_filter = 1
#net.ipv4.conf.default.arp_filter = 1
#net.ipv4.conf.all.rp_filter = 1
#net.ipv4.conf.default.rp_filter =1
****

net.ipv4.conf.all.arp_filter = 1 seems not to work, still getting
answers for all Intrfaces from eth0. Any Ideas?

Thanks in Advance for your Help!

Regards,

--
Adem Sen