multiple vlan from multiple ports connecting to router through a single interface

[MATT ALLEN]

I recently received a Catalyst 3850-24t-s with IP Base license to configure to work with some network upgrades we are wanting to do. I work for a small ISP and we are a FTTH network using Trident7 chassis from Pace networks. the connections from the chassis are sent from a switch module that provides connection for the entire chassis through a single ethernet connection. To decrease our broadcast domain we are needing to break the connection to the chassis into several VLAN, one per card in the chassis. in doing this I need to send 18 vlan per chassis to the Catalyst switch which should be no problem. the problem i am running into is connecting all the interfaces that feed the chassis to a single interface that connects to the router and also be able to use a single DHCP server. i have made a simple network diagram to help better understand what I am talking about. Any help would be greatly appreciated. thank you in advance.

Matt 

[MATT ALLEN]

I have come up with a plan for the migration. The switch module on the trident 7 has multiple ports I will configure a separate port for the new vlan configuration and also slowly remove ip addresses from our pool to create the smaller subnets so I can move customers a little at a time. It will definitely be tedious but I am sure we can handle it

[Jon Marshall]

Okay, well good luck with the migration and hope it all works out.

Jon

[MATT ALLEN]

All you guys gave been amazingly helpful. If there is anyway I can help you guys out let me know.

[Richard Burts]

Matt

It sounds like you have a good plan that should work. I am glad that we have been able to straighten out these issues. These forums are an excellent place to learn about networking and to share what we have learned. I hope to see you continue to actively participate in the forums.

HTH

Rick

[MATT ALLEN]

Well poop. That is not what I wanted to hear but, I don't guess there is any way around it. Breaking the ip addresses into subnets will be a challenge because some cards have more customers attached to them than others, and we don't have enough ip addresses to make all subnets uniform

[Richard Burts]

Matt

I sympathize that this was not what you want to hear. But it is the reality.

I am sure that changing provisioning to implement the new method will be complex (and probably tedious). It might be a bit easier if you had a new card which you could configure as a separate vlan and then incrementally move customer from an existing card to the new card. And when that card was empty configure it as a separate vlan, and then incrementally move customer from some other card onto this card. If you do not have a new card then perhaps you could identify some card which is less densely populated which you could change over and then incrementally move customer from another card onto this card.

It is not necessarily a requirement that all subnets be the same size. It is easier to design, and easier to manage if subnets are the same size. But it is not a requirement. You can have some subnets smaller and some subnets larger. As you design the subnets that you want to use just bear in mind the size of subnets given by the various subnet masks

255.255.254.0 gives 512 addresses (would you need anything larger than this?)

255.255.255.0 gives 256 addresses

255.255.255.128 gives 128 addresses

255.255.255.192 gives 64 addresses

255.255.255.224 gives 32 addresses

(would you have any need for subnets smaller than this?) 

HTH

Rick

[Jon Marshall]

Matt

Don't want to distract from this line of troubleshooting but just a quick question.

Did you add a route to the router for the new IP subnet eg.

"ip route 192.168.2.0 255.255.255.248 192.168.2.253"

Jon

[MATT ALLEN]

this is what I have configured on the switch with no traffic making it from 1/0/2 Router Port to 1/0/3 port connected to trident 7. I have checked the port coming out of the trident 7 with wireshark and the traffic is on vlan 302 but, still not able to reach the router. 

here is the config I have on the switch not sure if I am missing something, well obviously I am because it doesn't work.

show running config

interface GigabitEthernet1/0/2
 no switchport
 ip address 192.168.2.253 255.255.255.0

 
 interface Vlan302
 ip address 192.168.1.1 255.255.255.0

 interface GigabitEthernet1/0/3
 switchport access vlan 302
 switchport trunk allowed vlan 302
 switchport mode access

 
 
 ip default-gateway 192.168.2.254

 
 show ip route
 
 Gateway of last resort is 192.168.2.254 to network 0.0.0.0

S*    0.0.0.0/0 [1/0] via 192.168.2.254
      192.168.1.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.1.0/24 is directly connected, Vlan302
L        192.168.1.1/32 is directly connected, Vlan302
      192.168.2.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.2.0/24 is directly connected, GigabitEthernet1/0/2
L        192.168.2.253/32 is directly connected, GigabitEthernet1/0/2

192.168.2.254 is the IP address of the router

[Richard Burts]

For the devices connected in VLAN 302 on Trident 7 what is their default gateway?

HTH

Rick

[MATT ALLEN]

192.168.2.254 is the default gateway

[Richard Burts]

You have answered a different question from the one that I asked. You have told us what is the default gateway for the switch. What I asked is what is the default gateway for the devices connected on Trident 7 (in vlan 302)? And while I am asking about that environment what would be the IP address and subnet mask of a device connected on Trident 7?

HTH

Rick