OSPF on C3750 sends Hello's. C4948 isn't accepting or receiving any. What could be the issue?

Tom · ‎07-10-2020

Hello,

OSPF Hello packets are being sent out from one router however the second nor any of the other routers aren't picking them up. I've tried to change a few items based on what I've read online however can't get a handle on this. Hoping someone can point me in the right direction.

Issue: C3750 is sending out Hello packets. C4948 isn't receiving any or accepting any. Neither are any of the other routers. Why?

Details:

See attached .docx file.

---------------------------

The effect is that I can't ping VLAN5, for example, from mdscisco02 switch:

mdscisco02#ping 10.3.0.15

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.3.0.15, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
mdscisco02#

but I can locally on mdscisco01, where they're defined locally:

mdscisco01#ping 10.3.0.15

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.3.0.15, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/9 ms
mdscisco01#

.6 is an Asus router running Quagga. .7 is another Asus router running Quagga. These too cannot get VLAN2-5 routes. I'm more interested about getting mdscisco01 and mdscisco02 working. Thinking the solution will also work for the .6 and .7 routers.

Attached a topology diagram. There is a slight difference though. A number of physical ports from Server 2 and Server 3 are connected to the C4948 now.

balaji.bandi · ‎07-10-2020

Do you have any network topology how these devices connected? what is the 192.168.0.6 ?

also good to have .6 IP address device config along with show cdp neig information.

BB

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Martin L · ‎07-10-2020

%OSPF-4-NONEIGHBOR: Received database description from unknown neighbor 192.168.0.7

it appears you have 4th device with OSPF ID 192.168.0.7, right? the 3750 config you pasted is from ospf ID 192.168.0.1 , so where is 0.7?

Regards, ML
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Tom · ‎07-10-2020

Just edited the original post. Totally forgot to attach the image. Please take a look now.

Tom · ‎07-10-2020

Additional info:

Updated the .docx attachments in original post with show ip ospf database router output.

Reading on network type mismatches on the side to see if it has any relevance to this scenario. So thought o include this as well. https://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/7112-26.html

This all used to work. I enabled trunking on the rest of the interfaces for these servers to allow VLAN 1-5 traffic through the use of VMware VNIC's. ESXi runs on the servers shown in the diagram. However, after that change, this was still working. A sudden power outage overnight a couple of days ago wreaked havoc though. I wouldn't think this outage had anything to do with it though.

Example change:

interface GigabitEthernet1/39
switchport access vlan 5
switchport trunk encapsulation dot1q
switchport trunk native vlan 5
switchport trunk allowed vlan 1-5
switchport mode trunk

Tom · ‎07-10-2020

Hmm, the router elected as DR is not adjacent to C3750 that's running VLAN 2 - 5. Perhaps a Designated Router issue? .7 is listed as a DR however mdscisco01 sees mdscisco02 as a DR but mdscisco02 sees .7 as a DR. Still not clear 100% if this is the cause. Perhaps F/W is preventing proper election?

AC-R68U (Internet)

INTERNET-ASUS# show ip ospf database

       OSPF Router with ID (192.168.0.6)

                Router Link States (Area 0.0.0.0)

Link ID         ADV Router      Age  Seq#       CkSum  Link count
192.168.0.1     192.168.0.1       35 0x8000069a 0x3433 6
192.168.0.3     192.168.0.3     1121 0x80000061 0x7131 2
192.168.0.6     192.168.0.6      752 0x80000379 0xad62 1
192.168.0.7     192.168.0.7     1046 0x8000007a 0xb25c 1

                Net Link States (Area 0.0.0.0)

Link ID         ADV Router      Age  Seq#       CkSum
192.168.0.7     192.168.0.7     1046 0x8000006c 0x06b7


INTERNET-ASUS# sh ip ospf neighbor

Neighbor ID     Pri State           Dead Time Address         Interface            RXmtL RqstL DBsmL
192.168.0.1       1 2-Way/DROther     33.827s 192.168.0.1     br0:192.168.0.6          0     0     0
192.168.0.3       1 Full/Backup       35.286s 192.168.0.3     br0:192.168.0.6          0     0     0
192.168.0.7       1 Full/DR           38.983s 192.168.0.7     br0:192.168.0.6          0     0     0
INTERNET-ASUS#

AC-R68U (Secondary)

SECONDARY-HOME# show ip ospf database

       OSPF Router with ID (192.168.0.7)

                Router Link States (Area 0.0.0.0)

Link ID         ADV Router      Age  Seq#       CkSum  Link count
192.168.0.1     192.168.0.1       41 0x8000069a 0x3433 6
192.168.0.3     192.168.0.3     1127 0x80000061 0x7131 2
192.168.0.6     192.168.0.6      760 0x80000379 0xad62 1
192.168.0.7     192.168.0.7     1051 0x8000007a 0xb25c 1

                Net Link States (Area 0.0.0.0)

Link ID         ADV Router      Age  Seq#       CkSum
192.168.0.7     192.168.0.7     1051 0x8000006c 0x06b7


SECONDARY-HOME# sh ip ospf neighbor

Neighbor ID     Pri State           Dead Time Address         Interface            RXmtL RqstL DBsmL
192.168.0.1       1 Init/DROther      37.605s 192.168.0.1     br0:192.168.0.7          0     0     0
192.168.0.3       1 Full/Backup       37.741s 192.168.0.3     br0:192.168.0.7          0     0     0
192.168.0.6       1 Full/DROther      33.595s 192.168.0.6     br0:192.168.0.7          0     0     0

SECONDARY-HOME#

MDSCISCO01 (C3750)

mdscisco01#show ip ospf database

            OSPF Router with ID (192.168.0.1) (Process ID 1)

                Router Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum Link count
192.168.0.1     192.168.0.1     11          0x8000069A 0x003433 6
192.168.0.3     192.168.0.3     1098        0x80000061 0x007131 2
192.168.0.6     192.168.0.6     731         0x80000379 0x00AD62 1
192.168.0.7     192.168.0.7     1023        0x8000007A 0x00B25C 1

                Net Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum
192.168.0.7     192.168.0.7     1023        0x8000006C 0x0006B7
mdscisco01#sh ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
192.168.0.3       1   FULL/DR         00:00:37    192.168.0.3     Vlan1
192.168.0.6       1   2WAY/DROTHER    00:00:32    192.168.0.6     Vlan1
192.168.0.7       1   DOWN/DROTHER       -        192.168.0.7     Vlan1
mdscisco01#

MDSCISCO02 (C4948)

mdscisco02#show ip ospf database

            OSPF Router with ID (192.168.0.3) (Process ID 2)

                Router Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum Link count
192.168.0.1     192.168.0.1     7           0x8000069A 0x003433 6
192.168.0.3     192.168.0.3     1092        0x80000061 0x007131 2
192.168.0.6     192.168.0.6     726         0x80000379 0x00AD62 1
192.168.0.7     192.168.0.7     1018        0x8000007A 0x00B25C 1

                Net Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum
192.168.0.7     192.168.0.7     1018        0x8000006C 0x0006B7
mdscisco02#sh ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
192.168.0.1       1   FULL/DROTHER    00:00:36    192.168.0.1     Vlan1
192.168.0.6       1   FULL/DROTHER    00:00:32    192.168.0.6     Vlan1
192.168.0.7       1   FULL/DR         00:00:31    192.168.0.7     Vlan1
mdscisco02#

paul driver · ‎07-10-2020

Hello

Please attach any further configuration to a file as it will save on viewing a very large post

Just looking at your config it seems you have a lot of trunks and extended vlans across a routed access layer design which you cannot do so i'm not sure what you are trying to accomplish

Suggest you tidy your configuration up so each switch has a L3 svi connection for its ospf peering and and then any additional L3 svis for the access layer pertaining to that specific switch can then be advertised via ospf (these cannot be extended across multiple switch's)

remove any static default routes and secondary ip addressing then test again

Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

Tom · ‎07-11-2020

Trying to digest your comments in light of what I'm trying to do. Are you saying I need matching SVI's on the C4948 router as well as the Asus routers? I never had to do that before and the VLAN's were available from anywhere on my network.

Each ESXi physical host is connected to the two Cisco switches through 4 physical cables. VLAN 1-5 needs to be available to each ESXi host allowing me to create a Virtual Machine Port Group for each VLAN. I have 4 ESXi hosts in this config. (Just 3 are shown in the topology, however, but there's a 4th similarly connected to what's in the topology. )

Physical cables are not evenly split across the two Cisco switches, however. Well aware it's not super ideal.

Now, mind you, this used to work a few days ago w/ the SVI's as defined in the setup. The only thing I did was to add trunking to physical ESXi connections I noticed I had missed ( Meaning if a cable went bad, the other 3 physical cables going to that physical ESXi host wouldn't be able to carry VLAN 2-5 ). The second thing I did was to reload (restart) the C3750 , C4948 and the .6 Asus router. I haven't restarted the .7 for two days. The SVI and VLAN definitions haven't changed in that time.

So I have to have trunking all the way through otherwise ESXi's can't access those VLAN's.

Only thing I could see as a possible culprit is something like this:

https://www.certificationkits.com/cisco-ccie-why-do-routes-appear-in-the-ospf-database-but-not-in-the-routing-tab/

1) Asus 192.168.0.6 thinks DR is Asus 192.168.0.7
2) mdscisco01 thinks it's DR is mdscisco02 ( 192.168.0.3 )

3) mdscisco02 thinks it's DR is Asus 192.168.0.7

4) Asus 192.168.0.7 is (trying to? ) acting as the Designated Router.

Hoping this will give more context to the configuration and what I'm trying to do.

An earlier post where we discussed an earlier config I had is here:

https://community.cisco.com/t5/routing/inter-vlan-routing-can-ping-default-vlan-ip-from-other-vlan-s/td-p/3992294/page/5

Good point on the long post. I've cleaned it up and tossed the configs into separate word documents.

Thx,
TK

Tom · ‎07-11-2020

Fixed it!

All I did was restart the Asus .7 router. A new election took place making mdscisco02 ( 192.168.0.3) the DR.

All of a sudden, all the VLAN's were working correctly.

Asus .6 Router ( Quagga, Internet Facing )

ASUS-06-ROUTER# sh ip ospf neighbor

Neighbor ID     Pri State           Dead Time Address         Interface            RXmtL RqstL DBsmL
192.168.0.1       1 Full/DROther      31.713s 192.168.0.1     br0:192.168.0.6          0     0     0
192.168.0.3       1 Full/DR           34.467s 192.168.0.3     br0:192.168.0.6          0     0     0
192.168.0.7       1 Full/DROther      30.195s 192.168.0.7     br0:192.168.0.6          0     0     0
ASUS-06-ROUTER# sh ip route
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, P - PIM, A - Babel,
       b - BATMAN, N - NHRP,
       > - selected route, * - FIB route

K>* 0.0.0.0/0 via 123.123.123.97, vlan2
O>* 10.0.0.0/24 [110/11] via 192.168.0.1, br0, 00:05:10
O>* 10.1.0.0/24 [110/11] via 192.168.0.1, br0, 00:05:10
C>* 10.1.1.0/24 is directly connected, tun2
O>* 10.2.0.0/24 [110/11] via 192.168.0.1, br0, 00:05:10
O>* 10.3.0.0/24 [110/11] via 192.168.0.1, br0, 00:05:10
C>* 123.123.123.96/27 is directly connected, vlan2
K * 127.0.0.0/8 is directly connected, lo
C>* 127.0.0.0/8 is directly connected, lo
O   192.168.0.0/24 [110/10] is directly connected, br0, 00:05:10
C>* 192.168.0.0/24 is directly connected, br0
C>* 192.168.45.0/24 is directly connected, wl0.1
C>* 192.168.75.0/24 is directly connected, wl1.1
ASUS-06-ROUTER#

Asus .7 Router ( FRRouting )

ASUS-07-ROUTER# sh ip ospf neighbor

Neighbor ID     Pri State           Dead Time Address         Interface            RXmtL RqstL DBsmL
192.168.0.1       1 2-Way/DROther     37.881s 192.168.0.1     br0:192.168.0.7          0     0     0
192.168.0.3       1 Full/DR           30.847s 192.168.0.3     br0:192.168.0.7          0     0     0
192.168.0.6       1 Full/Backup       31.613s 192.168.0.6     br0:192.168.0.7          0     0     0

ASUS-07-ROUTER#
ASUS-07-ROUTER#
ASUS-07-ROUTER#
ASUS-07-ROUTER# sh ip route
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
       T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
       F - PBR, f - OpenFabric,
       > - selected route, * - FIB route, q - queued route, r - rejected route

O   0.0.0.0/0 [110/10] via 192.168.0.6, br0, 00:04:03
K>* 0.0.0.0/0 [0/0] via 192.168.0.6, br0, 00:04:15
O>* 10.0.0.0/24 [110/11] via 192.168.0.1, br0, 00:04:04
O>* 10.1.0.0/24 [110/11] via 192.168.0.1, br0, 00:04:04
O>* 10.1.1.0/24 [110/20] via 192.168.0.6, br0, 00:04:03
O>* 10.2.0.0/24 [110/11] via 192.168.0.1, br0, 00:04:04
O>* 10.3.0.0/24 [110/11] via 192.168.0.1, br0, 00:04:04
O>* 123.123.123.96/27 [110/20] via 192.168.0.6, br0, 00:04:03
K>* 127.0.0.0/8 [0/0] is directly connected, lo, 00:04:15
O   192.168.0.0/24 [110/10] is directly connected, br0, 00:04:04
C>* 192.168.0.0/24 is directly connected, br0, 00:04:15
O>* 192.168.45.0/24 [110/20] via 192.168.0.6, br0, 00:04:03
O>* 192.168.75.0/24 [110/20] via 192.168.0.6, br0, 00:04:03
ASUS-07-ROUTER#

mdscisco01 ( C3750 )

mdscisco01#sh ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
192.168.0.3       1   FULL/DR         00:00:32    192.168.0.3     Vlan1
192.168.0.6       1   FULL/BDR        00:00:34    192.168.0.6     Vlan1
192.168.0.7       1   2WAY/DROTHER    00:00:39    192.168.0.7     Vlan1
mdscisco01#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is 192.168.0.6 to network 0.0.0.0

O E2 192.168.75.0/24 [110/20] via 192.168.0.6, 00:03:57, Vlan1
O E2 192.168.45.0/24 [110/20] via 192.168.0.6, 00:03:57, Vlan1
     10.0.0.0/24 is subnetted, 5 subnets
C       10.2.0.0 is directly connected, Vlan4
C       10.3.0.0 is directly connected, Vlan5
O E2    10.1.1.0 [110/20] via 192.168.0.6, 00:03:57, Vlan1
C       10.0.0.0 is directly connected, Vlan2
C       10.1.0.0 is directly connected, Vlan3
     123.0.0.0/27 is subnetted, 1 subnets
O E2    123.123.123.96 [110/20] via 192.168.0.6, 00:03:57, Vlan1
C    192.168.0.0/24 is directly connected, Vlan1
S*   0.0.0.0/0 [1/0] via 192.168.0.6
mdscisco01#

mdscisco02 (C4948)

mdscisco02#sh ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
192.168.0.1       1   FULL/DROTHER    00:00:39    192.168.0.1     Vlan1
192.168.0.6       1   FULL/BDR        00:00:33    192.168.0.6     Vlan1
192.168.0.7       1   FULL/DROTHER    00:00:37    192.168.0.7     Vlan1
mdscisco02#
mdscisco02#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route

Gateway of last resort is 192.168.0.6 to network 0.0.0.0

O E2 192.168.75.0/24 [110/20] via 192.168.0.6, 00:03:52, Vlan1
O E2 192.168.45.0/24 [110/20] via 192.168.0.6, 00:03:52, Vlan1
     10.0.0.0/24 is subnetted, 5 subnets
O       10.2.0.0 [110/2] via 192.168.0.1, 00:03:52, Vlan1
O       10.3.0.0 [110/2] via 192.168.0.1, 00:03:52, Vlan1
O E2    10.1.1.0 [110/20] via 192.168.0.6, 00:03:52, Vlan1
O       10.0.0.0 [110/2] via 192.168.0.1, 00:03:52, Vlan1
O       10.1.0.0 [110/2] via 192.168.0.1, 00:03:52, Vlan1
     123.0.0.0/27 is subnetted, 1 subnets
O E2    123.123.123.96 [110/20] via 192.168.0.6, 00:03:52, Vlan1
C    192.168.0.0/24 is directly connected, Vlan1
S*   0.0.0.0/0 [1/0] via 192.168.0.6
mdscisco02#

Now the questions and followup I have is:

1) There were multiple DR's. Why? Possibly a F/W issue blocking elections?

2) Why did Asus .07 not generate proper link states? What's missing here?

Thx,

TK