Troubleshooting

IP Routing Troubleshooting

Related SMT screens and CI commands:

- SMT Menu 2

- ip route stat /* display ip route table and statistic counters */
- ip route errcnt disp /* display ip route error counters */
- ip route errcnt clear /* clear ip route error counters */

- sys filter disp /* display filter statistic counters */
- sys filter clear /* clear filter statistic counters */

IP Routing problem causes

An IP packet for the LAN destination should be routed to the LAN interface ( enif0 in Prestige ), and IP packet for a remote node destination should be sent to the WAN interface if the connection is up, or else the packet will trigger an outcall to that remote node ( if the remote node is not set for 'incoming' only in Call Direction. ) If a packet cannot be routed or cannot trigger a call to remote node, the reason may be due to:

- routing table problem
- the packet has been filtered
- cannot trigger the outcall or the outcall failed due to the reason stated in previous chapter ( Incoming only remote node, Black List, Call Budget, or PPP negotiation failed. )

Steps to verify IP routing problem

(1) check if there is any routing error ('ip route errcnt disp').
(2) check if the counter of the specified route increased ('ip route status').
(3) check if any filter counter increased ('sys filter disp').
(4) check if there is any LAN or WAN problem ( refer to sessions: LAN or WAN connection)

< Example >
1. Clear the error counter and display it to verify all counters are 0.

`P2864> ip route errcnt cl` `P2864> ip route errcnt dis` `last route error code = 0` `ipRouteFail_Disable 0 ipRouteFail_PktLen 0` `ipRouteFail_Header 0 ipRouteFail_CkSum 0` `ipRouteFail_OptLen 0 ipRouteFail_OptSRoute 0` `ipRouteFail_OptSSRoute 0 ipRouteFail_OptRRoute 0` `ipRouteFail_TTL 0 ipRouteFail_No_Route 0` `ipRouteFail_Wan_Route 0 ipRouteFail_RnNull 0` `ipRouteFail_DF 0 ipRouteFail_Fragment 0`

2. Display the IP routing table, and check the 'Use' field for the 'problem' route. We assume that we are troubleshooting the route to 100.1.1.1 and trying to figure out why the call was not triggered to the remote node.

`P2864>` `P2864> ip route st` `Dest FF Len Interface Gateway Metric stat Timer Use` `204.247.203.191 00 32 enif0 204.247.203.183 1 0015 0 0` `204.247.203.128 00 26 enif0 204.247.203.183 1 0023 0 0` `100.0.0.0 00 8 wanIdle 100.1.1.1 2 0023 0 0` `default 00 0 wanIdle Internet 2 0023 0 0`

3. Do a PING to that remote node (IP address 100.1.1.1) from the Prestige directly. ( You can do it from the LAN also. ) Check the routing table again

`306Z> ip ping 100.1.1.1` `Resolving 100.1.1.1... 100.1.1.1` `306Z>` `306Z> ip route st` `Dest FF Len Interface Gateway Metric stat Timer Use` `204.247.203.191 00 32 enif0 204.247.203.183 1 0015 0 0` `204.247.203.128 00 26 wanIdle 204.247.203.167 2 0023 0 0` `100.0.0.0 00 8 wanIdle 100.1.1.1 2 0023 0 3` `default 00 0 wanIdle Internet 2 0023 0 0`

We can see the 'Use' increased from 0 to 3. This is correct, since each 'ip ping' command will try to send 3 packets. So no problem in IP routing.

4. Check the Error counters

`p2864> ip route errcnt disp` `last route error code = a <--an hex value index point to the last error` `ipRouteFail_Disable 0 (index 0) ipRouteFail_PktLen 0(index1)` `ipRouteFail_Header 0 (index 2) ipRouteFail_CkSum 0` `ipRouteFail_OptLen 0 ipRouteFail_OptSRoute 0` `ipRouteFail_OptSSRoute 0 ipRouteFail_OptRRoute 0` `ipRouteFail_TTL 0 ipRouteFail_No_Route 0` `ipRouteFail_Wan_Route 3 <-+ ipRouteFail_RtType 0` `ipRouteFail_DF 0 | ipRouteFail_Fragment 0` `|` `| This counter is increased by 1`

This ipRouteFail_Wan_Route means routing cannot get a WAN resource to dial out. You can go to Menu 24.1 and verify if both B channels are up already or if the Link is 'Down'.

< Example >
1. If the routing table show the 'Use' is the same as before the PING. ( Or any other traffic that you think should route and trigger the outcall. ) Furthermore, the error counters are still 0's.

`Prestige> ip route st` `Dest FF Len Interface Gateway Metric stat Timer Use` `204.247.203.191 00 32 en0if 204.247.203.183 1 0015 0 0` `204.247.203.128 00 26 wanIdle 204.247.203.167 2 0023 0 0` `100.0.0.0 00 8 wanIdle 100.1.1.1 2 0023 0 3` `default 00 0 wanIdle Internet 2 0023 0 0`

2. You may want to verify if you have plugged in any filters for that remote node or LAN.

`Prestige> sys filter sw on` `Prestige> sys filter disp` `Drop 0 Forward 0` `SetNotConfig 0 SetNotActive 0` `NonRuleMatch 0 InvalidSet 0` `GenMatch 0 GenNotMatch 0` `IpMatch 0 IpDefaultMatch 0` `IpDefaultNotMatch 0 IpSourceAddr 0` `IpDestAddr 0 IpSourceRoute 0` `IpTcpConn 0 IpSourcePort 0` `IpDestPort 0 IpProtocol 0` `IpxMatch 0 IpxDefaultMatch 0` `IpxDefaultNotMatch 0 IpxPacketType 0` `IpxDestNetwork 0 IpxDestNode 0` `IpxDestSocket 0 IpxSourceNetwork 0` `IpxSourceNode 0 IpxSourceSocket 0`

3. Start a PING or start the traffic from the LAN side to trigger the outcall, and then display the
filter counters again. If the 'Drop' field show some numbers there, then it means that the packet
has been filter out, so no outcall was made when the packet was sent to the Prestige.

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