ā06-12-2012 03:59 AM - edited ā03-07-2019 07:12 AM
Hi,
I want to know that after enabling the HSRP , whether both the routers(active & standby) are using virtual IP for routing the packets or can it use one of the its assigned IP.
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ā06-12-2012 04:07 AM
Hello Nitin,
Any router in a standby group is fully reachable under its real IP address and this IP address remains functional regardless of the HSRP. In other words, you can always use these real IP address to contact the routers or to perform routing via these IP addresses as default gateways.
In addition, the Active router also uses the virtual IP address and can be contacted using that IP address.
Does this answer your question?
Best regards,
Peter
ā06-12-2012 04:15 AM
Welcome back my friend. So glad to see u again
ā06-12-2012 04:27 AM
HI Nitin,
I am agree with Peter.
Using HSRP, a set of routers work in concert to present the illusion of a single virtual router to the hosts on the LAN. This set is known as an HSRP group or a standby group.A single router elected from the group is responsible for forwarding the packets that hosts send to the virtual router.This router is known as the active router.Another router is elected as the standby router. In the event that the active router fails, the standby assumes the packet forwarding duties of the active router. Although an arbitrary number of routers may run HSRP, only the active router forwards the packets sent to the virtual router.
To minimize network traffic, only the active and the standby routers send periodic HSRP messages once the protocol has completed the election process. If the active router fails, the standby router takes over as the active router. If the standby router fails or becomes the active router, another router is elected as the standby router.
They usually use the real ip address of the router to communicate via default gateway( HSRP hello packets).
Regards
Plz rate if it helps.
ā06-13-2012 03:21 AM
Hi Nitin,
Configure your Eth 1, 2, 3 ,4 & 5 to have Gateway IP of 10.32.23.49 and I guess then everything should work as a charm...
HTH,
Smitesh
PS: Please rate helpful posts...
ā06-13-2012 12:51 PM
Hello Nitin,
I agree with Smitesh. Your Linux should be using only one default gateway - the vIP address 10.32.23.49.
Please note that there are two incorrect aspects of your current configuration:
Best regards,
Peter
ā06-12-2012 04:07 AM
Hello Nitin,
Any router in a standby group is fully reachable under its real IP address and this IP address remains functional regardless of the HSRP. In other words, you can always use these real IP address to contact the routers or to perform routing via these IP addresses as default gateways.
In addition, the Active router also uses the virtual IP address and can be contacted using that IP address.
Does this answer your question?
Best regards,
Peter
ā06-12-2012 04:15 AM
Welcome back my friend. So glad to see u again
ā06-12-2012 03:09 PM
Hello Kishore,
Thank you buddy! It's still difficult for me to get back to CSC as often as I would like to but I hope to see things improve a bit in the next couple of days.
Best regards,
Peter
ā06-12-2012 04:27 AM
HI Nitin,
I am agree with Peter.
Using HSRP, a set of routers work in concert to present the illusion of a single virtual router to the hosts on the LAN. This set is known as an HSRP group or a standby group.A single router elected from the group is responsible for forwarding the packets that hosts send to the virtual router.This router is known as the active router.Another router is elected as the standby router. In the event that the active router fails, the standby assumes the packet forwarding duties of the active router. Although an arbitrary number of routers may run HSRP, only the active router forwards the packets sent to the virtual router.
To minimize network traffic, only the active and the standby routers send periodic HSRP messages once the protocol has completed the election process. If the active router fails, the standby router takes over as the active router. If the standby router fails or becomes the active router, another router is elected as the standby router.
They usually use the real ip address of the router to communicate via default gateway( HSRP hello packets).
Regards
Plz rate if it helps.
ā06-12-2012 04:47 AM
thanks for reply ...
Below are the some analysis (through wireshark) on each linux interface. It seem that each interface is communicating with only one particular IP address .
Before HSRP Disable:
eth2 (10.32.23.55)
10.32.23.55 ---- ARP request(unicast) ---->> 10.31.22.197 (Degault gateway)
10.32.23.55 <<---- ARP reply(unicast) ---- 10.31.22.197 (Degault gateway)
eth3 (10.32.23.54)
10.32.23.54 ---- ARP request(unicast) ---->> 10.31.11.70 (router)
10.32.23.54 <<---- ARP reply(unicast) ---- 10.31.11.70 (router)
eth4 (10.32.23.53)
10.32.23.53 ---- ARP request(unicast) ---->> 10.31.13.76 (router)
10.32.23.53 <<---- ARP reply(unicast) ---- 10.31.13.76 (router)
eth5 (10.32.23.53)
10.32.23.52 ---- ARP request(unicast) ---->> 10.31.24.72 (router)
10.32.23.52 <<---- ARP reply(unicast) ---- 10.31.24.72 (router)
After HSRP Enable:
eth2 (10.32.23.55)
10.32.23.55 ---- ARP request(unicast) ---->> 10.31.22.197 (Degault gateway)
10.32.23.55 <<---- ARP reply(unicast) ---- 10.31.22.197 (Degault gateway)
(ARP request sent by Standby router )
10.32.23.52 (eth5) <<---- ARP request(Broadcast) ---- 10.32.23.50 (Standby router) virtual IP Address: 10.32.23.49
10.32.23.55 (eth2) <<---- ARP request(Broadcast) ---- 10.32.23.50 (Standby router) virtual IP Address: 10.32.23.49
Can you please suggest is it correct behavior ?
Can standby router send ARP request using its real IP ?
ā06-12-2012 03:21 PM
Hello Nitin,
I am having trouble understanding the different IP addresses displayed in your post. Would you please answer the following questions?
Thank you!
Best regards,
Peter
ā06-12-2012 09:33 PM
Thanks for reply ..........
Below are the IP details :
1. virtual IP address of the HSRP group is 10.32.23.49.
2. Individual IP addresses of the routers is 10.32.23.51 (active) & 10.32.23.50 (standby).
3. IP addresses of the individual Ethernet interfaces at the Linux box are:
ifconfig
eth0 Link encap:Ethernet HWaddr 00:25:B3:1C:B9:7E
inet addr:192.231.36.82 Bcast:192.231.36.255 Mask:255.255.255.0
inet6 addr: fe80::225:b3ff:fe1c:b97e/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
eth1 Link encap:Ethernet HWaddr 00:25:B3:1C:B9:7C
inet addr:10.32.23.56 Bcast:10.32.23.63 Mask:255.255.255.240
inet6 addr: fe80::225:b3ff:fe1c:b97c/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
eth2 Link encap:Ethernet HWaddr 00:1F:29:5A:B5:E9
inet addr:10.32.23.55 Bcast:10.32.23.63 Mask:255.255.255.240
inet6 addr: fe80::21f:29ff:fe5a:b5e9/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
eth3 Link encap:Ethernet HWaddr 00:1F:29:5A:B5:E8
inet addr:10.32.23.54 Bcast:10.32.23.63 Mask:255.255.255.240
inet6 addr: fe80::21f:29ff:fe5a:b5e8/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
eth4 Link encap:Ethernet HWaddr 00:1F:29:5A:B5:EB
inet addr:10.32.23.53 Bcast:10.32.23.63 Mask:255.255.255.240
inet6 addr: fe80::21f:29ff:fe5a:b5eb/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
eth5 Link encap:Ethernet HWaddr 00:1F:29:5A:B5:EA
inet addr:10.32.23.52 Bcast:10.32.23.63 Mask:255.255.255.240
inet6 addr: fe80::21f:29ff:fe5a:b5ea/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
4.
O100282:~# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.31.11.70 * 255.255.255.255 UH 0 0 0 eth3
10.31.24.72 * 255.255.255.255 UH 0 0 0 eth5
10.31.22.197 * 255.255.255.255 UH 0 0 0 eth2
10.31.13.76 * 255.255.255.255 UH 0 0 0 eth4
10.32.23.48 * 255.255.255.240 U 0 0 0 eth2
10.32.23.48 * 255.255.255.240 U 0 0 0 eth3
10.32.23.48 * 255.255.255.240 U 0 0 0 eth4
10.32.23.48 * 255.255.255.240 U 0 0 0 eth5
10.32.23.48 * 255.255.255.240 U 0 0 0 eth1
10.117.18.128 10.32.23.49 255.255.255.192 UG 0 0 0 eth1
10.17.5.128 10.32.23.49 255.255.255.128 UG 0 0 0 eth1
192.231.36.0 * 255.255.255.0 U 0 0 0 eth0
O100282:~# arp
Address HWtype HWaddress Flags Mask Iface
localhost (incomplete) eth0
10.31.24.72 ether 00:19:E8:77:86:08 C eth5
10.31.11.70 ether 00:19:E8:77:86:08 C eth3
10.32.23.49 ether 00:19:E8:77:86:08 C eth2
192.231.36.1 ether 00:1E:0B:F9:C3:B2 C eth0
10.32.23.49 ether 00:19:E8:77:86:08 C eth1
O100281 ether 00:23:7D:26:CA:66 C eth0
10.31.13.76 ether 00:19:E8:77:86:08 C eth4
10.31.22.197 ether 00:19:E8:77:86:08 C eth2
ā06-13-2012 03:21 AM
Hi Nitin,
Configure your Eth 1, 2, 3 ,4 & 5 to have Gateway IP of 10.32.23.49 and I guess then everything should work as a charm...
HTH,
Smitesh
PS: Please rate helpful posts...
ā06-13-2012 05:06 AM
Thanks for reply smitesh..
But each interface is configured with different gateway .
eth2 (10.32.23.55) -------->> 10.31.22.197 (Degault gateway)
eth3 (10.32.23.54) ---->> 10.31.11.70 (Degault gateway)
eth4 (10.32.23.53) ---->> 10.31.13.76 (Degault gateway)
eth5 (10.32.23.53) ---->> 10.31.24.72 (Degault gateway)
ā06-13-2012 05:15 AM
You need atleast one port to have gateway as VIP IP ( in your case 10.32.23.49)...
HTH,
Smitesh
ā06-13-2012 12:51 PM
Hello Nitin,
I agree with Smitesh. Your Linux should be using only one default gateway - the vIP address 10.32.23.49.
Please note that there are two incorrect aspects of your current configuration:
Best regards,
Peter
ā09-11-2012 09:56 PM
Hi Peter,
I added default gateway, but still i am facing same problem & below are the outputs:
Command: ip addr show
1: lo:
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: sit0:
link/sit 0.0.0.0 brd 0.0.0.0
3: eth0:
link/ether 00:25:b3:1c:b9:7e brd ff:ff:ff:ff:ff:ff
inet 192.231.36.82/24 brd 192.231.36.255 scope global eth0
inet6 fe80::225:b3ff:fe1c:b97e/64 scope link
valid_lft forever preferred_lft forever
4: eth2:
link/ether 00:1f:29:5a:b5:e9 brd ff:ff:ff:ff:ff:ff
inet 10.32.23.55/28 brd 10.32.23.63 scope global eth2
inet6 fe80::21f:29ff:fe5a:b5e9/64 scope link
valid_lft forever preferred_lft forever
5: eth3:
link/ether 00:1f:29:5a:b5:e8 brd ff:ff:ff:ff:ff:ff
inet 10.32.23.54/28 brd 10.32.23.63 scope global eth3
inet6 fe80::21f:29ff:fe5a:b5e8/64 scope link
valid_lft forever preferred_lft forever
6: eth4:
link/ether 00:1f:29:5a:b5:eb brd ff:ff:ff:ff:ff:ff
inet 10.32.23.53/28 brd 10.32.23.63 scope global eth4
inet6 fe80::21f:29ff:fe5a:b5eb/64 scope link
valid_lft forever preferred_lft forever
7: eth5:
link/ether 00:1f:29:5a:b5:ea brd ff:ff:ff:ff:ff:ff
inet 10.32.23.52/28 brd 10.32.23.63 scope global eth5
inet6 fe80::21f:29ff:fe5a:b5ea/64 scope link
valid_lft forever preferred_lft forever
8: eth1:
link/ether 00:25:b3:1c:b9:7c brd ff:ff:ff:ff:ff:ff
9: bond0:
link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
10: bond1:
link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
Command: ip route show table all
10.31.11.70 dev eth3 scope host
10.31.24.72 dev eth5 scope host
10.31.22.197 dev eth2 scope host
10.31.13.76 dev eth4 scope host
10.32.23.48/28 dev eth5 proto kernel scope link src 10.32.23.52
10.32.23.48/28 dev eth2 proto kernel scope link src 10.32.23.55
10.32.23.48/28 dev eth3 proto kernel scope link src 10.32.23.54
10.32.23.48/28 dev eth4 proto kernel scope link src 10.32.23.53
192.231.36.0/24 dev eth0 proto kernel scope link src 192.231.36.82
default via 10.32.23.49 dev eth5
default via 10.32.23.49 dev eth2
default via 10.32.23.49 dev eth3
default via 10.32.23.49 dev eth4
broadcast 127.255.255.255 dev lo table local proto kernel scope link src 127.0.0.1
broadcast 192.231.36.255 dev eth0 table local proto kernel scope link src 192.231.36.82
broadcast 10.32.23.63 dev eth5 table local proto kernel scope link src 10.32.23.52
broadcast 10.32.23.63 dev eth2 table local proto kernel scope link src 10.32.23.55
broadcast 10.32.23.63 dev eth3 table local proto kernel scope link src 10.32.23.54
broadcast 10.32.23.63 dev eth4 table local proto kernel scope link src 10.32.23.53
broadcast 192.231.36.0 dev eth0 table local proto kernel scope link src 192.231.36.82
local 192.231.36.82 dev eth0 table local proto kernel scope host src 192.231.36.82
broadcast 10.32.23.48 dev eth5 table local proto kernel scope link src 10.32.23.52
broadcast 10.32.23.48 dev eth2 table local proto kernel scope link src 10.32.23.55
broadcast 10.32.23.48 dev eth3 table local proto kernel scope link src 10.32.23.54
broadcast 10.32.23.48 dev eth4 table local proto kernel scope link src 10.32.23.53
local 10.32.23.55 dev eth2 table local proto kernel scope host src 10.32.23.55
local 10.32.23.54 dev eth3 table local proto kernel scope host src 10.32.23.54
local 10.32.23.53 dev eth4 table local proto kernel scope host src 10.32.23.53
broadcast 127.0.0.0 dev lo table local proto kernel scope link src 127.0.0.1
local 10.32.23.52 dev eth5 table local proto kernel scope host src 10.32.23.52
local 127.0.0.1 dev lo table local proto kernel scope host src 127.0.0.1
local 127.0.0.0/8 dev lo table local proto kernel scope host src 127.0.0.1
local ::1 via :: dev lo proto none metric 0 mtu 16436 advmss 16376 hoplimit 4294967295
local fe80::21f:29ff:fe5a:b5e8 via :: dev lo proto none metric 0 mtu 16436 advmss 16376 hoplimit 4294967295
local fe80::21f:29ff:fe5a:b5e9 via :: dev lo proto none metric 0 mtu 16436 advmss 16376 hoplimit 4294967295
local fe80::21f:29ff:fe5a:b5ea via :: dev lo proto none metric 0 mtu 16436 advmss 16376 hoplimit 4294967295
local fe80::21f:29ff:fe5a:b5eb via :: dev lo proto none metric 0 mtu 16436 advmss 16376 hoplimit 4294967295
local fe80::225:b3ff:fe1c:b97e via :: dev lo proto none metric 0 mtu 16436 advmss 16376 hoplimit 4294967295
fe80::/64 dev eth0 metric 256 expires 8531085sec mtu 1500 advmss 1440 hoplimit 4294967295
fe80::/64 dev eth5 metric 256 expires 8531106sec mtu 1500 advmss 1440 hoplimit 4294967295
fe80::/64 dev eth2 metric 256 expires 8531106sec mtu 1500 advmss 1440 hoplimit 4294967295
fe80::/64 dev eth4 metric 256 expires 8531106sec mtu 1500 advmss 1440 hoplimit 4294967295
fe80::/64 dev eth3 metric 256 expires 8531106sec mtu 1500 advmss 1440 hoplimit 4294967295
ff00::/8 dev eth0 metric 256 expires 8531085sec mtu 1500 advmss 1440 hoplimit 4294967295
ff00::/8 dev eth5 metric 256 expires 8531106sec mtu 1500 advmss 1440 hoplimit 4294967295
ff00::/8 dev eth2 metric 256 expires 8531106sec mtu 1500 advmss 1440 hoplimit 4294967295
ff00::/8 dev eth4 metric 256 expires 8531106sec mtu 1500 advmss 1440 hoplimit 4294967295
ff00::/8 dev eth3 metric 256 expires 8531106sec mtu 1500 advmss 1440 hoplimit 4294967295
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