help with a network design

[baselzind]

there is three networks a b c , where both network b and c share the same vlan 10 for servers. networks A reach network C through static routes. between network a and b there is  a L3 interfaces with the ip 10.10.10.1 and .2 and between network b and c there is a trunk and vlan 500 where at each side there is a interface vlan 500 which i use for routing as well. So if i want to reach the server vlan 10  at network c192.168.10.0/24 i have a static route at network A saying ip route 192.168.10.0 x.x.x.x next hop is 10.10.10.2 and then between b and c there is a static route saying ip route 192.168.10.0 x.x.x.x next hop is 10.10.11.2.

Now what is needed is to change the link between network b and c into normal trunk and remove the previously mentioned routing with vlan 500 , im wondering how it will affect network "a" reaching network c? like when traffic from network a destined to 192.168.10.0/24 reachs 10.10.10.2 how will the switch in network b deals with it? espacially if i remove  "ip route 192.168.10.0 x.x.x.x next hop is 10.10.11.2"

[balaji.bandi]

If you changing from Layer 3 toi Layer 2 Trunk, you do not neet static Route for the 192.168.1.0/24 network towards network C.

Make sure you stretch the VLAN 10 in the Trunk (VLAN  allow List should be good  - if you just use just trunk, then all vlan allowed)

- By the way do you have VLAN 10 SVI created both network B Switch and network C switches ?

 - Why in your diagram show both has same IP ? (is this typo ?)

[baselzind]

sorry i was just trying to show info about vlan 10 and its subnet. there is an svi for vlan 10 in network C but not sure about network B. the thing is when i change the link between network b and c to layer 2 trunk and remove the static route from network b what will the switch in network b "network b is basically one switch"  do when it receives traffic destined to vlan 10 on network c from network a, coming on the interface 10.10.10.2 in case there isnt a svi for vlan 10 on network b switch? am i suppose to create one on network b switch?

[balaji.bandi]

 there is an svi for vlan 10 in network C but not sure about network B

hope you manage the switch infra, so you should have information, so we can suggest best we can

Ok take only network c has SVI VLAN 10 192.168.1.0/24

Layer 2 VLAN will be extended to networkB

If network B and Network A do not aware Network C IP address 192.168.1.0/24 the traffic will be black holed.

So the switches neet to be aware where the destination and routing aware.

Do you have config all devices, show run post here, we can tweak and suggest what configured on the device for now.

[baselzind]

atm the customer isnt providing the information and im not handling the infra, im only supposed to assist incase changing the link between network b and c to layer2 goes wrong. so according to what you have said about the traffic going into a blackhole, am i supposed to create an svi for vlan 10 on the network b switch to avoid this?

[balaji.bandi]

if you extending Layer 2 to network B, Creating VLAN 10 IP in network B will be aware 192.168.1.0/24 (think that you have ip routing enabled (and you are not disabling).