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New Member

Routing Issues - Two companies migration

I have the scenario as pictured in the attachment.

Company A migration with Company B

I built a layer 2 trunk between the Company A and B core switches. Both switches can talk over the newly built Layer2 trunk. Both switches are same VTP domain and running same STP. All the vlans in Company A advertise to ISP via eigrp and they want to keep eigrp running in future too, similarly company B advertises its routes using BGP /MPLS.

After the migration I am not able to reach the new switch from NOC/Remote management [ packets dropping at Company B core ].What routing changes do I need to make on both core switches to make sure the new switch connected to Company A can be reached from Remote management. Attached the Configs files for both companies.

Challenge is: I cannot ask ISP to advertise company B’s subnets come through Company A Core router. A typical path to reach company B subnets in Company A is: to come from ISP-> Company B core-> laye2 trunk-> company A.

Example. To reach SW3[ 192.168.30.0/24] from Remote management, it has to go through MPLS cloud- ISPA-> Company B core-Via L2 trunk to Company A-> SW3.

Any help advise is appreciated.

Thanks

Blach.

10 REPLIES
New Member

Routing Issues - Two companies migration

Hi,

After a very lean understanding of your network I am able to figure out that you are missing a reverse route on your Company B core switch.

Just try to add a static route for your NOC and this should solve your problem.

Regards,

Pawan Sharma

http://www.ebrahma.com

New Member

Routing Issues - Two companies migration

I am not sure what you mean reverse route? Can you be more specific?I can reach anyof the Company B switches from NOC that are connected to Company B core router, The swich connected to Company A Core is no different than anyother switches that are connected to Company B core.

New Member

Routing Issues - Two companies migration

Hi,

By reverse route I mean, default gateway configuration the switch.

Regards,

Pawan Sharma

http://www.ebrahma.om

New Member

Routing Issues - Two companies migration

I do have default on each core switches to ISP; Sorry I did not include in the Configuration file.

Routing Issues - Two companies migration

Hi,

I did not understood where does stands the SVI ( interface vlan) for the new vlan (192.168.30.0/24) on Company A or B ?

Can you post from the Company B :

               show bgp all summ

Dan

New Member

Routing Issues - Two companies migration

Thanks for the reply. The SVI for company B's subnets is defined on company B core.The Idea is to use the span company B's subnets to company A.

Example:192.168.30.1[which is management vlan for switches in company B] is defined on core switch B. When a new switch is added to core switch A with management IP 192.168.30.4[example]. I cannot reach it from remote management.

On company core A I added the below static route for remote management/Noc subnet.[166.44.50.0].

Ip route 166.44.50.0 255.255.255.0 192.168.30.1

However when I tracert from Noc to new switch IP 192.168.30.4 , it drops at core B[ 192.168.30.1]

I am not sure what static route I have to add on core B to reach from 192.168.30.1 to 192.168.30.4 as I do not have any SVI defined .

Routing Issues - Two companies migration

Hi ,

If the new switch on company A has the default gateway 192.168.30.1 ( which is the SVI on Company B ) there is no need for a static route.

On company B :

       Can you ping the new switch from the Company B ?

       Is the SVI configured in the VRF ?

      Your interface toward the ISP in the VRF ?

       Is your BGP adjacency  with the BGP estableshed per address-family ipv4 vrf also on ipv4 unicast ? show bgp all summ

Dan

New Member

Re: Routing Issues - Two companies migration

If the new switch on company A has the default gateway 192.168.30.1 ( which is the SVI on Company B ) there is no need for a static route.

->I agree, However I already have an default gatway defined to ISP for any routes that doesnt getadvertised via eigrp.I dont think it makes any sense to add one more default route to SVI on company B.

Apart from I explained above in my messages ,I bascially want to manage the Company core A switch by assigning the management IP from the management vlan[192.168.30.0.24/subnet].and currently it drops after Company B when traced from Noc. Iknow there is route missing and I am not what should the route from company B to reach company A switch

On company B :

       Can you ping the new switch from the Company B ?

-> I can ping the new switch from company B and viceversa, but not from NOC

       Is the SVI configured in the VRF ?

-> Yes it is configured in VRF

      Your interface toward the ISP in the VRF ?

-> Yes

       Is your BGP adjacency  with the BGP estableshed per address-family ipv4 vrf also on ipv4 unicast ? show bgp all summ

->Yes

For address family: IPv4 Unicast
BGP router identifier 192.168.10.3, local AS number YYYYY
BGP table version is 5, main routing table version 5

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.10.1   4 XXXXX       0       0        0    0    0 never    Idle
192.168.10.2   4 XXXXX       0       0        0    0    0 never    Idle

For address family: VPNv4 Unicast
BGP router identifier 192.168.10.3, local AS number YYYYY
BGP table version is 1280, main routing table version 1280
109 network entries using 16259 bytes of memory
190 path entries using 10880 bytes of memory
18/9 BGP path/bestpath attribute entries using 2520 bytes of memory
16 BGP AS-PATH entries using 168 bytes of memory
1 BGP community entries using 24 bytes of memory
1 BGP extended community entries using 24 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 24850 total bytes of memory
BGP activity 789/324 prefixes, 1930/1170 paths, scan interval 15 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
192.168.10.1   4 XXXXX  447234  445672     1280    0    0 46w6d          78
192.168.10.2   4 XXXXX  443791  445863     1280    0    0 53w0d          78

Routing Issues - Two companies migration

By route back I think he is implying that you have a way there, but have you checked the routing tables to verify a way back?  Just another place to start.

New Member

Routing Issues - Two companies migration

yeah... thats exactly what I was trying to say...

Regards,

Pawan Sharma

http://www.ebrahma.com

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