From: Nambi Appachigounder (nambi_gct@yahoo.co.in)
Date: Mon Jan 23 2006 - 08:00:57 GMT-3
Hi Nick,
Seems you have some very old IOS version.When the VRRP
VIP is equal to the interface IP, VRRP priority
becomes 255.It implies that you can not preempt VRRP
Master role(becasue configurable priority value is
1-254)in this scenario.Hence the duplicate address
issue will not occur.
An example is available in the below link.
http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapter09186a008042fbd9.html#wp1054103
Or RFC2338 - Section 5.3.4
Thanks,
Nambi
--- Nick <seajay76@nate.com> wrote:
> Hi, Nambi!
>
> I set up the lab and test with HSRP & VRRP.
>
> First, just as you mentioned, HSRP didn't allow me
> to configure VIP
>
> with the same ip address that the physical interface
> has.
>
> Second, however, still some questionable thing with
> VRRP.
>
> Here is the Configuration. When I lowered the active
> router's priority
>
> the VRRP failover works fine, but MAC dup messages
> appear.
>
> What do you think Nambi? Did I configure wrong??
>
> Thank you in advance.
>
> Nick
>
> ### R3 ###
>
> R3#show run int e0/0
>
> interface Ethernet0/0
> ip address 3.3.10.3 255.255.255.0
> vrrp 1 ip 3.3.10.3
> vrrp 1 priority 110
> end
>
> Rack3R3#show vrrp
> Ethernet0/0 - Group 1
> State is Master
> Virtual IP address is 3.3.10.3
> Virtual MAC address is 0000.5e00.0101
> Advertisement interval is 1.000 sec
> Preemption is enabled
> min delay is 0.000 sec
> Priority is 90
> Master Router is 3.3.10.3 (local), priority is 110
>
> Master Advertisement interval is 1.000 sec
> Master Down interval is 3.648 sec (expires in
> 3.580 sec)
>
> ### R4 ###
>
> R4#show run int e0/0
>
> interface Ethernet0/0
> ip address 3.3.10.4 255.255.255.0
> vrrp 1 ip 3.3.10.3
> end
>
> Rack3R4#show vrrp
> Ethernet0/0 - Group 1
> State is Backup
> Virtual IP address is 3.3.10.3
> Virtual MAC address is 0000.5e00.0101
> Advertisement interval is 1.000 sec
> Preemption is enabled
> min delay is 0.000 sec
> Priority is 100
> Master Router is 3.3.10.3 , priority is 110
> Master Advertisement interval is 1.000 sec
> Master Down interval is 3.609 sec
>
> ### CHANGING the PRIORITY ###
>
> Rack3R3#conf t
> Enter configuration commands, one per line. End
> with CNTL/Z.
> Rack3R3(config)#int e0/0
> Rack3R3(config-if)#vrrp 1 pri 90
> Rack3R3(config-if)#end
> Rack3R3#
> Rack3R3#show clock
> *14:16:46.667 UTC Tue Mar 2 1993
> Rack3R3#clear arp
> Rack3R3#
> *Mar 2 14:16:44.836: %IP-4-DUPADDR: Duplicate
> address 3.3.10.3 on Ethernet0/0, sourced by
> 0000.5e00.0101
> Rack3R3#
> *Mar 2 14:17:15.290: %IP-4-DUPADDR: Duplicate
> address 3.3.10.3 on Ethernet0/0, sourced by
> 0000.5e00.0101
> Rack3R3#
>
>
> ----- Original Message -----
> From: "Nambi Appachigounder" <nambi_gct@yahoo.co.in>
> To: "Nick" <seajay76@nate.com>; "Cisco
> certification" <ccielab@groupstudy.com>
> Sent: Sunday, January 22, 2006 11:29 PM
> Subject: Re: Question for Nambi~~~ VRRP vs Standby--
> ReallY??
>
>
> > Hi Nick,
> >
> > I absolutely have no clue about the behaviour you
> are
> > observing.
> > My response was based on my understanding of HSRP
> RFC
> > 2281.
> >
> > This RFC defines the VIP as follows.
> >
> > On a particular LAN, multiple hot standby groups
> may
> > coexist and
> > overlap. Each standby group emulates a single
> virtual
> > router. For each standby group, a single
> well-known
> > MAC address is allocated to the group, as well as
> an
> > IP address. The IP address SHOULD belong to the
> > primary subnet in use on the LAN, but MUST differ
> from
> > the addresses allocated as interface addresses on
> all
> > routers and hosts on the LAN, including virtual IP
> > addresses assigned to other HSRP groups.
> >
> > http://www.faqs.org/rfcs/rfc2281.html
> >
> > Regards,
> > Nambi
> > --- Nick <seajay76@nate.com> wrote:
> >
> >> Thank you Nambi!
> >>
> >> Unfortunately, when I configured the HSRP in that
> >> way below.
> >>
> >> I didn't encounter any error messages.
> >>
> >> However, I can reproduce it in the lab. It may
> take
> >> some time though.
> >>
> >> I'll post the result on the GS.
> >>
> >> Thank you again.
> >>
> >> Regards,
> >> Nick
> >>
> >> P.S. I'v never read any RFC before. Think it's
> time
> >> to read one :)
> >>
> >> ----- Original Message -----
> >> From: "Nambi Appachigounder"
> <nambi_gct@yahoo.co.in>
> >> To: "Nick" <seajay76@nate.com>; "Cisco
> >> certification" <ccielab@groupstudy.com>
> >> Sent: Sunday, January 22, 2006 9:51 PM
> >> Subject: Re: Question for Nambi~~~ VRRP vs
> Standby--
> >> ReallY??
> >>
> >>
> >> > Hi Nick,
> >> >
> >> > AFAIK HSRP will not allow us to use the
> interface
> >> > address as Virtual IP.It is very surprising
> that
> >> you
> >> > are able to do this.
> >> > Can you please shut/no shut e0/0 of R4 and see
> if
> >> you
> >> > see any error message.This may be the reason
> why
> >> you
> >> > get the duplicate address problem.
> >> >
> >> > In VRRP duplicate address problem will not
> >> occur.The
> >> > protocol itslef is designed like that.Please
> check
> >> > Section 4.1 of RFC 2338.
> >> > Also in VRRP you can track an interface with
> the
> >> track
> >> > object command.
> >> >
> >> > Regards,
> >> > Nambi.
> >> > --- Nick <seajay76@nate.com> wrote:
> >> >
> >> >> Hi, Nambi!
> >> >>
> >> >> Thank you for your explanation.
> >> >>
> >> >> In fact, I was able to CONFIGURE the virtual
> IP
> >> with
> >> >> the interface IP in HSRP configuration.
> >> >>
> >> >> Following are the configurations;
> >> >>
> >> >>
> >> >> LINK1 LINK2
> >> >> | |
> >> >> | |
> >> >> (s0/0) (s0/0)
> >> >> R4 R5
> >> >> (e0/0) (e0/0)
> >> >> +-----------+
> >> >>
> >> >>
> >> >> R4
> >> >>
> >> >> int s0/0
> >> >> desc ## LINK1 ##
> >> >> ip add 4.0.0.1 255.255.255.0
> >> >> !
> >> >> int e0/0
> >> >> ip add 10.0.0.1 255.255.255.0
> >> >> standby ip 10.0.0.1
> >> >> standby priority 110
> >> >> standby track serial 0/0 50
> >> >> standby preempt
> >> >>
> >> >> R5
> >> >>
> >> >> int s0/0
> >> >> desc ## LINK2 ##
> >> >> ip add 5.0.0.1 255.255.255.0
> >> >> !
> >> >> int e0/0
> >> >> ip add 10.0.0.2 255.255.255.0
> >> >> standby ip 10.0.0.1
> >> >> standby preempt
> >> >>
> >> >> But, here when I tried kill the s0/0 on R4,
> and
> >> both
> >> >> the routers showed
> >> >>
> >> >> the duplicate ARP messages for 10.0.0.1.
> >> >>
> >> >> So, if I can set the VIP with the physical
> >> interface
> >> >> IP,
> >> >>
> >> >> does it mean the VRRP can prevent the ARP dup
> >> >> problem?
> >> >>
> >> >> Since the VRRP doesn't support the "track"
> >> feature,
> >> >>
> >> >> it seems there,anyway, would be only one
> >> situation
> >> >> when R4 takes the active role,
> >> >>
> >> >> which is R4 e0/0 failure.
> >> >>
> >> >> Would give me some help on this??
> >> >>
> >> >> Regards,
> >> >> Nick
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >> ----- Original Message -----
> >> >> From: "Nambi Appachigounder"
> >> <nambi_gct@yahoo.co.in>
> >> >> To: "Nick" <seajay76@nate.com>;
> >> >> <ccielab@groupstudy.com>
> >> >> Sent: Sunday, January 22, 2006 4:56 PM
> >> >> Subject: Re: VRRP vs Standby-- ReallY??
> >> >>
> >> >>
> >> >> > Yes.Lets say the address assignment is as
> >> follows.
> >> >> > R4 => 10.0.0.1/8
> >> >> > R5 => 10.0.0.2/8
> >> >> > End host => 10.0.0.3/8
> >> >> >
> >> >> > We need to configure VRRP on R4 and R5 with
> the
> >> >> > statement "vrrp 10 ip 10.0.0.1".In the end
> host
> >> >> you
> >> >> > need to give the gateway address as
> >> >> "10.0.0.1".Even if
> >> >> > R4 fails R5 will respond to packets sent to
> >> >> 10.0.0.1
> >> >> >
> >> >> > I think we don't need to bother abt IRDP
> when
> >> we
> >> >> go
> >> >> > for HSRP/VRRP.
> >> >> > To overcome the inefficiencies with Proxy
> ARP
> >> and
> >> >> IRDP
> >> >> > we chose HSRP/vrrp.Please correct me
> otherwise.
> >> >> >
> >> >> > Regards,
> >> >> > Nambi.
> >> >> > --- Nick <seajay76@nate.com> wrote:
> >> >> >
> >> >> >> Wow, I didn't know that.
> >> >> >>
> >> >> >> Then, if requirements are like following,
> the
> >> >> >> solution would be to configure VRRP!!
> >> >> >>
> >> >> >> Requirement
> >> >> >> (1) Configure gateway redundancy so that
> >> clients
> >> >> in
> >> >> >> VLAN X can use R4 as a primary default
> >> gateway,
> >> >> >> and R5 in case of failure of R4.
> >> >> >>
> >> >> >> (2) The clients don't support IRDP.
> >> >> >>
> >> >> >> Am I right??
> >> >> >>
> >> >> >> Regards,
> >> >> >> Nick
> >> >> >>
> >> >> >>
> >> >> >> ----- Original Message -----
> >> >> >> From: "Nambi Appachigounder"
> >> >> <nambi_gct@yahoo.co.in>
> >> >> >> To: "Scott Morris" <swm@emanon.com>;
> >> >> >>
> <RIDNEY_M_LAUDIANO.TTSP@ts.tsuneishi.co.jp>;
> >> >> >> "'Jtheunissen'" <jtheunissen@dodo.com.au>;
> >> >> >> <ccielab@groupstudy.com>
> >> >> >> Sent: Friday, January 20, 2006 9:49 PM
> >> >> >> Subject: RE: VRRP vs Standby
> >> >> >>
> >> >> >>
> >> >> >> > Also in VRRP, VIP can be the same as
> >> interface
> >> >> IP
> >> >> >> but
> >> >> >> > in hsrp it is not possible.
> >> >> >> >
> >> >> >> > Regards,
> >> >> >> > Nambi
> >> >> >> > --- Scott Morris <swm@emanon.com> wrote:
> >> >> >> >
> >> >> >> >> Vrrp preempt IS indeed enabled by
> default,
> >> but
> >> >> >> you
> >> >> >> >> can change the delay if
> >> >> >> >> you want.
> >> >> >> >> Tracking was introduced in 12.3(2)T, so
> if
> >> you
> >> >> >> are
> >> >> >> >> on a 12.4 router, you
> >> >> >> >> will have that functionality.
> >> >> >> >>
> >> >> >> >> Otherwise, it's pretty similar. (No
> >> >> >> authentication
> >> >> >> >> by default, unlike HSRP)
> >> >> >> >>
> >> >> >> >> Scott
> >> >> >> >>
> >> >> >> >> -----Original Message-----
> >> >> >> >> From: nobody@groupstudy.com
> >> >> >> >> [mailto:nobody@groupstudy.com] On Behalf
> Of
> >> >> >> >>
> RIDNEY_M_LAUDIANO.TTSP@ts.tsuneishi.co.jp
> >> >> >> >> Sent: Thursday, January 19, 2006 9:16 PM
> >> >> >> >> To: Jtheunissen; ccielab@groupstudy.com
> >> >> >> >> Subject: Re: VRRP vs Standby
> >> >> >> >>
> >> >> >> >> and a quick guess:
> >> >> >> >>
> >> >> >> >> vrrp routers are configured to preempt
> by
> >> >> default
> >> >> >> >> and most importantly it
> >> >> >> >> has no mechanism to track interfaces
> >> >> >> >>
> >> >> >> >>
> >> >> >> >> "Jtheunissen" <jtheunissen@dodo.com.au>
> >> wrote
> >> >> on
> >> >> >> >> 01/20/2006 09:52:27 AM:
> >> >> >> >>
> >> >> >> >> ) Just a quick question what is the
> leading
> >> >> >> >> difference between VRRP and
> >> >> >> >> ) Standby options for fault tolerence ?.
> >> >> >> >>
> >> >> >> >> ) Jeff
> >> >> >> >>
> >> >> >> >> )
> >> >> >>
> >> ________________________________________________
> >> >> >> >>
> >> >> >> >> ) Message sent using Dodo Internet
> Webmail
> >> >> Server
> >> >> >> >>
> >> >> >> >> )
> >> >> >> >>
> >> >> >> >
> >> >> >>
> >> >> >
> >> >>
> >> >
> >>
> >
>
This archive was generated by hypermail 2.1.4 : Wed Feb 01 2006 - 07:45:50 GMT-3