• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 1435
  • Last Modified:

2611XM/3548XL - Subinterfaces and VLANs

I am experiencing issues assigning IP address when attempting to trunk multiple VLANs up to a single CISCO 2611 using subinterfaces.....

I have a CISCO 2611 XM and a CISCO 3548 XL...I am trying to use FA 0/0 with subinterfaces (2611) and vlan access [desired ports] (3548) to carry multiple VLANs.

192.168.100.0/24 [VLAN 100 on the 3548]
192.168.200.0/24 [VLAN 200 on the 3548]

-==2611==-
int fa 0/0.1
encap dot1q 100
ip address 192.168.100.0 255.255.255.0

int fa 0/0.2
encap dot1q 200
ip address 192.168.200.0 255.255.255.0

-==3548==-
int fa 0/1
switchport mode trunk (allowed all)

int fa 0/3
switchport mode access
switchport access vlan 100

I do not have any speed/duplex issues or any up/down issues.....I have dhcp pools setup for both and dhcp-server/networks setup per VLAN (problem ???)....I currently have no L3 management IP established on the 3548 so int VLAN1 remains up up....Obviously as soon as I revert back to a single network on fa 0/0 with no sub-ifs it works fine.

I have seen several proposed solution regarding "secondary" interfaces resolving several peoples issues with physical interface limitations but unfortunately that hasn't worked for me.
0
ciscowannabe
Asked:
ciscowannabe
  • 2
1 Solution
 
pjtemplinCommented:
What is the problem?  Amongst other things, you might need "swit tru enc dot1q" (and if so, "swit tru enc dot1q non" would probably be better) on 3548 int f0/1 to force the trunking protocol.  Routers don't participate in DTP, so a switch expecting DTP might not trunk or might attempt ISL instead of dot1q.

You may also want to shutdown the 3548 int VLAN1 and create/setup an int VLAN 100 ...OR... 200, so that you can telnet to the 3548.
0
 
calvinetterCommented:
  Look at your configured IPs on the subinterfaces:
int fa 0/0.1
ip address 192.168.100.0 255.255.255.0  <- network address; should be something like 192.168.100.1 ...

int fa 0/0.2
ip address 192.168.200.0 255.255.255.0  <- network address; should be something like 192.168.200.1 ...

  Then you can deal with routing between VLANs:
Workstations on VLAN 100 would have their default gateway set to: 192.168.100.1
Workstations on VLAN 200 would have their default gateway set to: 192.168.200.1

On the switch, you could do this in order to remotely manage it:
  int vlan 100
  ip address 192.168.100.2 255.255.255.0
  no shut

  ip default-gateway 192.168.100.1

cheers
0
 
ciscowannabeAuthor Commented:
calvinetter - The IP addresses on the sub-ifs are .1 - sorry for the misinformation.

I'm checking into the above solution recommendations. Thanks,
0
 
ciscowannabeAuthor Commented:
Forgetting about lack of DTP was it....I forced trunk encap and that did it....thanks pjtemplin.
0

Featured Post

How to change the world, one degree at a time.

By embracing technology, we can solve even the biggest problems—including the gender gap.  By earning a degree from WGU, you have an opportunity to gain the knowledge, credentials, and experience it takes to thrive in today’s high-growth IT industry.

  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now