From: nenad pudar (nenad.pudar@gmail.com)
Date: Mon Jan 02 2006 - 03:02:09 GMT-3
Sorry should be
If I change the statement
ip nat outside source static udp 172.16.32.129 520 224.0.0.10 520
to
ip nat inside source static udp 172.16.32.130 <http://172.16.32.129/> 520
224.0.0.10 520
that router translate source address 172.16.32.130 <http://172.16.32.129/>to
224.0.0.10 which is the action supposed to happen once the packet hits
incoming interface.
On 1/2/06, nenad pudar <nenad.pudar@gmail.com> wrote:
>
> And this logic seems to be OK
> If I change the statement
> ip nat outside source static udp 172.16.32.129 520 224.0.0.10 520
> to
>
> ip nat inside source static udp 172.16.32.129 520 224.0.0.10 520
>
> while keeping the ip nat outside on outgoing interface I see in the log
>
> that router translate source address 172.16.32.129 to 224.0.0.10 which
> is the action supposed to happen once the packet hits incoming interface.
>
>
>
> nenad
>
>
>
>
> On 1/2/06, nenad pudar <nenad.pudar@gmail.com> wrote:
> >
> > Hi Wang
> >
> > You are right I see the same thing
> >
> > : EIGRP: Ignore unicast Hello from Virtual-Access1 172.16.32.130
> >
> > Definitelly this will not work with eigrp
> >
> > Eigrp is very strange .on the other side I see the neigbor up ,but one
> > message in the queue
> >
> > #R1sh ip eigrp neighbors
> > IP-EIGRP neighbors for process 2
> > H Address Interface Hold Uptime SRTT RTO Q
> > Seq Type
> > (sec) (ms) Cnt
> > Num
> > 0 172.16.32.129 Vi1 12 00:00:40 1 5000 1
> > 0
> >
> > Still
> > I do not fully get the logic behind this
> > ip nat outside source static udp 172.16.32.129 520 224.0.0.10 520
> >
> > Since the source address from this side is not 172.16.32.129 but .130
> > nothing will happend while traffic leaving the outside interface.
> > The only explanation I have that the implicit action will do the thing
> > ,meaning the packet coming on inside interface with destination of
> > 224.0.0.10 will be translated to the destination 172.16.32.129 which is
> > exactly what we need .
> > But there is no inside interface
> > My only guess since the router generates the packet (it is not forwarded
> > across the router) we do not need to specify the inside interface.
> >
> > In the case of RIP it will accept unicast hello and send the reply with
> > source 172.16.32.129 and dest 172.16.32.130 ,nat will not be involved
> > again and everything works fine.
> >
> >
> >
> >
> >
> > Nenad
> >
> >
> >
> >
> > On 1/2/06, Wang Dehong-DWANG1 < Dehong.Wang@motorola.com> wrote:
> > >
> > >
> > > The statement works well with RIP but not EIGRP. For some reason, the
> > > outside global ip adress is not translated into outside local address
> > > in
> > > one direction(anomaly for multicast?), so EIGRP rejects unicast packet
> > > while expecting multicast packet. RIP does not seem to care this so it
> > > works.
> > >
> > > How is the way I understand the statement, this is outside source
> > > address translation. When the packet from source 23.23.23.3 hit
> > > outside
> > > interface, it is translated into outside local address.
> > >
> > > HTH..
> > >
> > > - Dehong
> > > -
> > > Mar 13 04:24:02.656 : NAT: s=23.23.23.2, d=224.0.0.10-> 23.23.23.3 [0]
> > > Mar 13 04:24:02.656: EIGRP: Sending HELLO on FastEthernet0/0
> > > Mar 13 04:24:02.656: AS 1, Flags 0x0, Seq 0/0 idbQ 0/0 iidbQ un/rely
> > >
> > > 0/0
> > > Mar 13 04:24:03.201: EIGRP: Received UPDATE on FastEthernet0/0 nbr
> > > 23.23.23.3
> > > Mar 13 04:24:03.201: AS 1, Flags 0x1, Seq 23/0 idbQ 0/0
> > > Mar 13 04:24:03.201: EIGRP: Neighbor( 23.23.23.3) not yet found
> > > Mar 13 04:24:03.281: EIGRP: Received HELLO on FastEthernet0/0 nbr
> > > 23.23.23.3
> > > Mar 13 04:24:03.281: AS 1, Flags 0x0, Seq 0/0 idbQ 0/0
> > > Mar 13 04:24:03.281: EIGRP: Ignore unicast Hello from FastEthernet0/0
> > > 23.23.23.3
> > > Mar 13 04:24:03.522: EIGRP: Sending HELLO on Loopback0
> > >
> > > -----Original Message-----
> > > From: nobody@groupstudy.com [mailto: nobody@groupstudy.com] On Behalf
> > > Of
> > > nenad pudar
> > > Sent: Sunday, January 01, 2006 9:54 PM
> > > To: ccielab@groupstudy.com
> > > Subject: Re: Unicasting eigrp messages using nat -do not get it
> > >
> > > Just realized that eigrp with conifg below is nor working properly.
> > > See few session flaps and more importantly I see no route exchanged be
> > >
> > > teen eigrp neighbors nenad
> > >
> > > On 1/1/06, nenad pudar <nenad.pudar@gmail.com> wrote:
> > > >
> > > > Hi guys
> > > >
> > > > I am trying to unicast the eigrp update between two neighbors using
> > > > nat It is working but I do not understand the principe behind this
> > > >
> > > > Here is the config
> > > > interface Virtual-Template1
> > > > bandwidth 512
> > > > ip address 172.16.32.130 255.255.255.192 ip nat outside
> > > > **************************************
> > > > ip authentication mode eigrp 2 md5
> > > > ip authentication key-chain eigrp 2 ccie ip summary-address eigrp
> > > 2
> > > > 10.17.2.0 255.255.255.0 5 ppp authentication chap PPP ppp chap
> > > > hostname r1 end
> > > >
> > > >
> > > >
> > > > ip nat outside source static 172.16.32.129 224.0.0.10
> > > > ********************
> > > >
> > > >
> > > > #R1sh ip eigrp neighbors
> > > > IP-EIGRP neighbors for process 2
> > > > H Address Interface Hold Uptime SRTT RTO
> > >
> > > Q
> > > > Seq Type
> > > > (sec) (ms)
> > > Cnt
> > > > Num
> > > > 0 172.16.32.129 Vi1 14 00:00:18 1 5000
> > >
> > > 1
> > > > 0
> > > > IP-EIGRP neighbors for process 3
> > > >
> > > > .855: NAT: s=172.16.32.130, d=224.0.0.10- >172.16.32.129 [0] Jan 2
> > > > 03:23: 46.199: NAT: i: eigrp (172.16.32.130 , 0) -> ( 224.0.0.10, 0)
> > > [0]
> > >
> > > > Jan 2 03:23:46.199: NAT: s=172.16.32.130 , d=224.0.0.10->
> > > 172.16.32.129
> > >
> > > > [0] Jan 2 03:23:50.783: NAT: i: eigrp ( 172.16.32.130, 0) ->
> > > > (224.0.0.10 , 0) [0] Jan 2 03:23:50.783: NAT: s=172.16.32.130 ,
> > > > d=224.0.0.10->172.16.32.129[0] Jan 2 03:23:55.535 : NAT: i: eigrp
> > > > (172.16.32.130 , 0) -> (224.0.0.10, 0) [0] Jan 2 03:23:55.535: NAT:
> > > > s= 172.16.32.130, d=224.0.0.10->172.16.32.129 [0] Jan 2 03:24:
> > > 00.271:
> > > > NAT: i: eigrp ( 172.16.32.130, 0) -> ( 224.0.0.10, 0) [0] Jan 2
> > > > 03:24:00.271: NAT: s=172.16.32.130 , d=224.0.0.10->172.16.32.129 [0]
> > > >
> > > > #R1sh ip nat translations
> > > > Pro Inside global Inside local Outside local
> > > > Outside global
> > > > --- 172.16.32.130 172.16.32.130 224.0.0.10
> > > > 172.16.32.129
> > > >
> > > > I did this following one similar example in Cisco book but I do not
> > > > get it
> > > >
> > > >
> > > > ip nat outside source static 172.16.32.129 224.0.0.10 statement
> > > > according to my understanding of how NAT works will:
> > > >
> > > > 1) Translate the source address 172.16.32.129 to 224.0.0.10 once the
> > > > packet hits outside interface
> > > > 2) It will also translate the destination address 224.0.0.10 to
> > > > 172.16.32.129 once the packet hits the inside interface
> > > >
> > > > Above you can see the nat log
> > > >
> > > > This statement
> > > >
> > > > Jan 2 03:23:46.199: NAT: s= 172.16.32.130,
> > > > d=224.0.0.10-> 172.16.32.129
> > > >
> > > > I can understand assuming that since the packet are locally
> > > generated
> > > > router "does not need explicitly defined inside interface"
> > > >
> > > > But I do not really get what is happening with the packet coming
> > > from
> > > > the other side
> > > >
> > > >
> > > > Anybody can help me about this one .
> > > >
> > > > thanks
> > > > nenad
> > >
> > >
> > > _______________________________________________________________________
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> > > http://www.groupstudy.com/list/CCIELab.html
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