IP Aliasing effective only after some time

Hi!
I am facing a problem with IP address aliasing. We are using 2 cards
in a 1+1 redundancy configuration.One card is active and the other one
is acting as standby for active. So whenever the active card fails
redundant will take over.Since we do not want external entities to be
aware of this switchover we use alias IP address. Our software assigns
alias IP address to the active card.So when there is a switchover
Alias IP address is dropped on the standby ( earlier Active) and
assigned to Active ( earlier standby). We are able to connect to the
newly active card using Alias IP address, but only after some time
(appr. 20-30 mins).
The alias IP address is configured on eth1:1.
Could this be an issue with router or IP address alasing?
The ifconfig o/p is attached below:
Redundant Card (before switchover)-
[root@redserver root]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref
Use Iface
172.25.78.0 * 255.255.255.0 U 0 0
0 eth0
192.168.100.0 * 255.255.255.0 U 0 0
0 eth1
127.0.0.0 * 255.0.0.0 U 0 0
0 lo
default 172.25.78.1 0.0.0.0 UG 0 0
0 eth0
[root@redserver root]# ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:0E:0C:37:F7:66
inet addr:172.25.78.199 Bcast:172.25.78.255
Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1477397 errors:0 dropped:0 overruns:0 frame:0
TX packets:627313 errors:0 dropped:0 overruns:0 carrier:1343
collisions:4947 txqueuelen:100
RX bytes:154157338 (147.0 Mb) TX bytes:211076973 (201.2 Mb)
Interrupt:19

eth1 Link encap:Ethernet HWaddr 00:0E:0C:37:F7:65
inet addr:192.168.100.16 Bcast:192.168.100.255
Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:112 errors:0 dropped:0 overruns:0 frame:0
TX packets:32 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:8288 (8.0 Kb) TX bytes:3040 (2.9 Kb)
Interrupt:18 Base address:0x3000 Memory:febe0000-fec00000

eth2 Link encap:Ethernet HWaddr 00:0E:0C:37:F7:64
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:100
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:17 Base address:0x3040 Memory:febc0000-febe0000

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:1055956 errors:0 dropped:0 overruns:0 frame:0
TX packets:1055956 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:149324666 (142.4 Mb) TX bytes:149324666 (142.4 Mb)

Active Card (before switchover)-
[root@actserver root]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref
Use Iface
172.25.78.0 * 255.255.255.0 U 0 0
0 eth0
192.168.100.0 * 255.255.255.0 U 0 0
0 eth1
172.25.0.0 * 255.255.0.0 U 0 0
0 eth1
127.0.0.0 * 255.0.0.0 U 0 0
0 lo
default 172.25.78.1 0.0.0.0 UG 0 0
0 eth0
[root@actserver root]# ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:0E:0C:37:FB:F2
inet addr:172.25.78.198 Bcast:172.25.78.255
Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:13060367 errors:0 dropped:0 overruns:0 frame:0
TX packets:9337957 errors:0 dropped:0 overruns:0
carrier:2991
collisions:7205 txqueuelen:100
RX bytes:1151852843 (1098.4 Mb) TX bytes:1435735429 (1369.2
Mb)
Interrupt:19 Base address:0x1000

eth1 Link encap:Ethernet HWaddr 00:0E:0C:37:FB:F1
inet addr:192.168.100.5 Bcast:192.168.100.255
Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:118 errors:0 dropped:0 overruns:0 frame:0
TX packets:46 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:9232 (9.0 Kb) TX bytes:4432 (4.3 Kb)
Interrupt:18 Base address:0x3000 Memory:febe0000-fec00000

eth1:1 Link encap:Ethernet HWaddr 00:0E:0C:37:FB:F1
inet addr:172.25.78.203 Bcast:172.25.255.255
Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:18 Base address:0x3000 Memory:febe0000-fec00000

eth2 Link encap:Ethernet HWaddr 00:0E:0C:37:FB:F0
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:100
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:17 Base address:0x3040 Memory:febc0000-febe0000

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:3639095 errors:0 dropped:0 overruns:0 frame:0
TX packets:3639095 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:494434843 (471.5 Mb) TX bytes:494434843 (471.5 Mb)

Redundant Card (after switchover)-


[root@redserver root]# ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:0E:0C:37:F7:66
inet addr:172.25.78.199 Bcast:172.25.78.255
Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1504059 errors:0 dropped:0 overruns:0 frame:0
TX packets:638893 errors:0 dropped:0 overruns:0 carrier:1358
collisions:4998 txqueuelen:100
RX bytes:156946803 (149.6 Mb) TX bytes:212281486 (202.4 Mb)
Interrupt:19

eth1 Link encap:Ethernet HWaddr 00:0E:0C:37:F7:65
inet addr:192.168.100.16 Bcast:192.168.100.255
Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:112 errors:0 dropped:0 overruns:0 frame:0
TX packets:32 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:8288 (8.0 Kb) TX bytes:3040 (2.9 Kb)
Interrupt:18 Base address:0x3000 Memory:febe0000-fec00000

eth1:1 Link encap:Ethernet HWaddr 00:0E:0C:37:F7:65
inet addr:172.25.78.203 Bcast:172.25.255.255
Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:18 Base address:0x3000 Memory:febe0000-fec00000

eth2 Link encap:Ethernet HWaddr 00:0E:0C:37:F7:64
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:100
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:17 Base address:0x3040 Memory:febc0000-febe0000

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:1084671 errors:0 dropped:0 overruns:0 frame:0
TX packets:1084671 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:153196071 (146.0 Mb) TX bytes:153196071 (146.0 Mb)

On Mon, 11 Oct 2004 03:12:24 -0700, Shailesh wrote:

> We are able to connect to the newly active card using Alias IP address,
> but only after some time (appr. 20-30 mins). The alias IP address is
> configured on eth1:1.

> Could this be an issue with router or IP address alasing?

Flush the ARP cache on the router when the interface goes down

--
Everybody needs a little love sometime; stop hacking and fall in love!

Geoffrey King <(E-Mail Removed)> wrote in message news:<(E-Mail Removed) dns.org>...
> On Mon, 11 Oct 2004 03:12:24 -0700, Shailesh wrote:
>
> > We are able to connect to the newly active card using Alias IP address,
> > but only after some time (appr. 20-30 mins). The alias IP address is
> > configured on eth1:1.
>
> > Could this be an issue with router or IP address alasing?
>
> Flush the ARP cache on the router when the interface goes down

Thanks Geoffrey!
But we do not have any control over the router.And AFAIK routers
update there tables frequently, so it should not make much time for
them to update their tables?
Is there a way the active card can broadcast some message that it is
the one holding IP address now?
Regards,
Shailesh

On Mon, 11 Oct 2004 16:03:06 -0700, Shailesh wrote:

> But we do not have any control over the router.And AFAIK routers
> update there tables frequently, so it should not make much time for
> them to update their tables?

About 10 - 20minutes. It depends how big the arp cache on the router is.

> Is there a way the active card can broadcast some message that it is
> the one holding IP address now?

No. You could maybe kludge something with arpd though?

--
The first time, it's a KLUDGE!
The second, a trick.
Later, it's a well-established technique!
-- Mike Broido, Intermetrics

>> Is there a way the active card can broadcast some message that it is
>> the one holding IP address now?
>
> No. You could maybe kludge something with arpd though?

We are using here heartbeat. one of it's advantages is the way it sends
out the arp address change for a certain ip address in case of a failover.
But attention: if the router is configured to not accept arp address
information on it's lan port, it won't update and you are still stuck with
your 20min of "downtime"

Frank