ISR 4331 -> dialer stay's up but no IP traffic

[Peter Spekreijse (keps)]

Hi,

I've a ISR 4331 running 15.5(3)S4b. Once in a while we loose the uplink connection. The dialer stays up but IP doesn't work anymore. Does anyone have a clue? I did search the bug database but found nothing.

Regards,

Peter.

[Giuseppe Larosa]

Hello @Peter Spekreijse (keps) ,

please post the configuration to see how you have configured DDR Dial on Demand Routing.

For new IOS releses the use of dialer watch and a watch-list is the recommended workaround.

With dialer watch the router checks the routing table to see if routes to be watched disappears.

In the classic DDR setup you use a floating static default route to trigger routing over the dialer interface.

ip route 0.0.0.0 0.0.0.0 Dialer1 220

this acts as a backup default route to be used.

do the dialer interface get an IP address ?

show interface dialer x

when it is up provides you an IP address ?

if using PPP looks for state OPEN for IPCP

Hope to help

Giuseppe

[Peter Spekreijse (keps)]

Hi,

The relevant portion of the config follows:

interface Dialer1
  mtu 1492
  ip address negotiated
  no ip redirects
  no ip unreachables
  no ip proxy-arp
  encapsulation ppp
  dialer pool 1
  dialer-group 1
  ppp authentication pap callin
  ppp pap sent-username <removed> password <removed>
  no cdp enable
  ip virtual-reassembly

ip route 172.31.255.139 255.255.255.255 Dialer1

dialer-list 1 protocol ip permit

172.31.255.139 is the BGP  neighbor we get a default route from.

Now and then the IP connectivity over the dialer stops. We can't ping our BGP neighbor. A shut / no shut on the dialer solves the problem.

I think it's a bug. But how do I find it in the database?

Regards,

[Giuseppe Larosa]

Hello @Peter Spekreijse (keps) ,

I don't understand your network scenario.

1) The dialer interface is used as a backup path or it is your primary path because you have a PPPoE connection to the internet?

2) the BGP peer has a fixed IP address, normally BGP allows sessions with static IP address, is your dialer interface getting always the same IP addres from the provider ?

3) >> Now and then the IP connectivity over the dialer stops. We can't ping our BGP neighbor. A shut / no shut on the dialer solves the problem.

I agree this looks like a SW issue unless the session is timed out by the ISP when you shut/unshut a new PPP session is started.

Contact the ISP and ask about their policies for this kind of service.

Hope to help

Giuseppe

[Peter Spekreijse (keps)]

Hi Giuseppe,

1. Its the primary connection. Its a private network. We've a 4G backup link.

2. We're always getting the same IP address from the provider (private space).

3. I already contacted the ISP.  No answers there.

Thanks for the reply.

Regards,

Peter.