3550 vlan question

Answered Question
May 18th, 2009
User Badges:

Hello, I am currently pursuing my CCNA and having a little problem with a config I am toying with.


I have a Cisco 3550 Switch and I have two subnets attached to it:


192.168.1.0/24 on interface FastEthernet 0/1 vlan 2 IP of 192.168.1.248

192.168.2.0/24 on interface FastEthernet 0/2 vlan 3 IP of 192.168.2.2


I would like to both subnets to use the same Internet connection which IP is 192.168.1.254 and on vlan2.


I set the vlan 3 clients default gateway to 192.168.2.2.


I also set a route in the Internet router to point all 192.168.2.0/24 traffic to 192.168.1.248.


Problem:


I have no problems getting vlan 2 out to the Internet, but cannot get vlan 3 out to the Internet.


See attached config.


Any help would be appreciated.





Attachment: 
Correct Answer by Richard Burts about 8 years 2 months ago

Brian


I have looked at the config that you posted and I do not believe that the problem is on your switch configuration. If VLAN 2 is in 192.168.1.x address space and is going to the Internet then somewhere it must be translated. And I am guessing that the translation is being done on 192.168.1.254.


And if VLAN 3 wants to get to the Internet then it also needs address translation. And I am guessing that 192.168.1.254 is configured to translate the 192.168.1.0 network and is not configured to translate the 192.168.2.0 network. If you add the translation for 192.168.2.0 then I would expect that VLAN 3 could get to the Internet as well as VLAN 2 can.


HTH


Rick

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)
Loading.
Jon Marshall Mon, 05/18/2009 - 11:44
User Badges:
  • Super Blue, 32500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN

Brian


Can your vlan 3 clients ping their default-gateway ie. 192.168.2.2 ?


If so then it could be a NAT issue with your Internet router. Could you post a sanitised version of the router config ?


Jon

2174252588 Mon, 05/18/2009 - 11:51
User Badges:

Yes the vlan 3 clients can ping their default gateway of 192.168.2.2.



Correct Answer
Richard Burts Mon, 05/18/2009 - 11:50
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN

Brian


I have looked at the config that you posted and I do not believe that the problem is on your switch configuration. If VLAN 2 is in 192.168.1.x address space and is going to the Internet then somewhere it must be translated. And I am guessing that the translation is being done on 192.168.1.254.


And if VLAN 3 wants to get to the Internet then it also needs address translation. And I am guessing that 192.168.1.254 is configured to translate the 192.168.1.0 network and is not configured to translate the 192.168.2.0 network. If you add the translation for 192.168.2.0 then I would expect that VLAN 3 could get to the Internet as well as VLAN 2 can.


HTH


Rick

Richard Burts Wed, 05/27/2009 - 18:51
User Badges:
  • Super Silver, 17500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN

Brian


I am glad that you got your issue resolved and that my suggestion pointed in the right direction. Thank you for using the rating system to indicate that your issue was resolved (and thanks for the rating). It makes the forum more useful when people can read about an issue and can know that they will read a response which pointed toward the successful resolution of the issue.


The forum is an excellent place to learn about Cisco networking. I encourage you to continue your participation in the forum.


HTH


Rick

Actions

This Discussion