DDR no working between spoke site

[kayih]

I have a little probleme.

I have a cisco 2600 router on my central site on Paris.

I have one cisco 1700 router on Milan and Venise site. Both router have a default route pointing on Paris. The two router cisco 1700 are connected via BRI interface to PARIS.

The problem is that user from Milan and Venise can't communicate. Paris can talk to Milan and Venise, but Venise can't talk Milan.

It seems that routing is not working properly. the Cisco 2600 have all routes and routing is activated.

is there something missing im my config ??

[Georg Pauwen]

Hello,

can you post the configurations of your routers ?

Regards,

GP

[kayih]

here are the config of the 3 devices, see attached file (config.txt) .

thanks

[Georg Pauwen]

Hello,

you only have one dialer interface configured at your hub site for both spoke sites. That means you can only talk to one site at a time, since dialer interfaces are point-to-point links by default. Try and add another dialer interface for the second hub site:

interface Dialer1

bandwidth 512

ip unnumbered Ethernet0/0

encapsulation ppp

dialer in-band

dialer idle-timeout 180

dialer fast-idle 60

dialer map ip 158.x.x.3 name kheops xxxx

dialer load-threshold 70 either

dialer-group 1

no cdp enable

ppp callback request

ppp authentication pap

no ppp chap wait

ppp pap sent-username RPRO-ANTILLES password xxxx

ppp multilink

!

interface Dialer2

bandwidth 512

ip unnumbered Ethernet0/0

encapsulation ppp

dialer in-band

dialer idle-timeout 180

dialer fast-idle 60

dialer map ip 10.99.1.1 name RGUYAG-PRO xxxxx

dialer load-threshold 70 either

dialer-group 1

no cdp enable

ppp callback request

ppp authentication pap

no ppp chap wait

ppp pap sent-username RPRO-ANTILLES password xxxx

ppp multilink

!

Make sure that your static routes point to the correct dialer interfaces once you have added the second one.

Can you try this and see if that works ?

Regards,

GP

[dbellaze]

You have some recursive information in your configurations, but they look correct. You do not have to create another dialer interface to get this to work.

First from the Milan router can you do normal and extended pings to the ethernet interface of the Venise router and vice versa?

Example - On Milan

Regular Ping

kheops#ping 10.99.1.1

Extended Ping

keops#ping

Protocol [ip]:

Target IP address: 10.99.1.1

Repeat count [5]:

Datagram size [100]:

Timeout in seconds [2]:

Extended commands [n]: yes

Source address or interface: 158.129.10.3

Type of service [0]:

Set DF bit in IP header? [no]:

Validate reply data? [no]:

Data pattern [0xABCD]:

Loose, Strict, Record, Timestamp, Verbose[none]:

Sweep range of sizes [n]:

If your pings are successful then routing is working between the sites.

If your pings don't work do a traceroute to the ethernet interface on the Milan router from the Venise router and vice versa and post the output.

Do extended traces to so that the source IP is the ethernet interface on the router you are doing the trace from.

Example- On Milan

Regular Trace

kheops# trace 10.99.1.1

Extended Trace

kheops#trace

Protocol [ip]:

Target IP address: 10.99.1.1

Source address: 158.129.10.3

kheops#

Please post the outputs from these tests.

Daniel

[Richard Burts]

I think there is a problem in the configuration of the venise router. In that config there is a default route pointing to bri 0, so packets from venise to milan would be sent to bri 0. But on bri 0 there is no map that indicates what to dial to get to address 158.129.10.3, there is only a map for 10.2.1.7

Probably the easiest way to fix this is to change the default router from:

ip route 0.0.0.0 0.0.0.0 BRI0

to:

ip route 0.0.0.0 0.0.0.0 10.2.1.7

HTH

Rick

[kayih]

The problem is not about DDR, this functionnality seems to work properly.

For example, when all BRI interfaces are down on all router : Paris, Venise, Milan (this is normal because there's no interesting trafic); and when I trie to ping Venise from Milan, the link between Paris and Milan is bring up and some second later the link between Paris and Venise is bring up too.

That why I said that DDR is walking.

However Routing is not working between Milan and Venise.

For example when All Bri interfaces are up, from Paris I can Ping Venise an Milan. but Venise can't ping Milan, despite all link are bring up correctly.

I have made a debug PPP, anything is ok.

I don't understand why these two sites can't communicate !!!

The problem is not at the layer 2 because the DDR walk when interesting trafic is present.

The problem is not at the layer 3 because the each spoke router have a default route to the Hub router, and the Hub router Known how to reach any remote site !!

I don't known what to do, may be an upgrade of the IOS.

thanks.

[Richard Burts]

Before you spend much time upgrading IOS or doing other things to investigate this problem, try the change that I suggested to make the default route point to the next hop address instead of just pointing at the interface.

HTH

Rick

[dbellaze]

Is the problem that Venise can't ping Milan, or is it in both directions?

Daniel

[kayih]

the problem is in both direction

[dbellaze]

Now that I look at it again, I think Rick is correct in the default route problem. By pointing your route to BRI0 it doesn't tell the router which dialer map to use, because there can be many dialer maps configured.

I think you should make the change that Rick suggested.

Daniel

[kayih]

ok, I going back to our customer site next week. I will try you suggest, and will tell you if it solve the problem.

Thank you every body for your help.