Sunderwood Posted July 4, 2008 Posted July 4, 2008 HI Im setting up a new classroom and i want to put them on a separate Vlan. The Problem: i have set the interface vlan up on the router and i know all this works fine because i have setup a port on that vlan and i get the correct address from the dhcp server... i then go to a switch which is 2 hops away, all the vlans are created correctly on the switches on route and all the links which are from the router are setup as trunks and allow all vlans. I connect a PC and the switch can't get a dhcp address? i set the port back to the default vlan and it gets an ip and works fine (so connectivity is ok) All the encapsulation is set to dot1q? any ideas?
EduTech Posted July 4, 2008 Posted July 4, 2008 Set up a static ip address and try and ping the switch from that machine. If that works, try and ping the router interface.. that is set up for that Vlan Regards James.
Sunderwood Posted July 7, 2008 Author Posted July 7, 2008 OK update!! I took my a new switch (erased Startup) and went down to the main router and bypassed to the switch in the middle. i then connected all the cables and configs the same as they are upstairs and all seems to be working fine? its until i go to the switch upstairs thats 2 hops away that i can not get an ip.. All links are set as trunks!!! What could be the issue?
spc-rocket Posted July 7, 2008 Posted July 7, 2008 OK update!! I took my a new switch (erased Startup) and went down to the main router and bypassed to the switch in the middle. i then connected all the cables and configs the same as they are upstairs and all seems to be working fine? its until i go to the switch upstairs thats 2 hops away that i can not get an ip.. All links are set as trunks!!! What could be the issue? Check to if: - The encapsulation is correct on all the trunk links - there are allowed vlans list on the trunks all from the router to the switch that is having issues - is the dhcp server on another vlan, if so enable the ip helper command in the the router. Ash.
Sunderwood Posted July 7, 2008 Author Posted July 7, 2008 Hi thanks for the reply. yer i have that all setup as follows: My interface on the router: interface Vlan4 description Technology Suite ip address 192.168.10.1 255.255.255.0 ip helper-address 172.28.47.29 ip helper-address 172.28.47.30 The status of the switchport on all the trunks: Name: Gi1/0/52 Switchport: Enabled Administrative Mode: trunk Operational Mode: trunk Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: dot1q Negotiation of Trunking: On Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Administrative Native VLAN tagging: enabled Voice VLAN: none Administrative private-vlan host-association: none Administrative private-vlan mapping: none Administrative private-vlan trunk native VLAN: none Administrative private-vlan trunk Native VLAN tagging: enable d Administrative private-vlan trunk encapsulation: dot1q Administrative private-vlan trunk normal VLANs: none Administrative private-vlan trunk private VLANs: none Operational private-vlan: none Trunking VLANs Enabled: ALL Pruning VLANs Enabled: 2-1001 Capture Mode Disabled Capture VLANs Allowed: ALL Protected: false Unknown unicast blocked: disabled Unknown multicast blocked: disabled Appliance trust: none i have checked all links and they are setup like this? What else could be wrong?
Sunderwood Posted July 7, 2008 Author Posted July 7, 2008 OK i think i have narrowed it down to the switches 2950's i have done the same configuration on a 2960 and i get an ip straight away. i can also ping the default gateway from every switch except the one i am trying to get working? Could it be a firmware upgrade?
MSGeek Posted August 30, 2008 Posted August 30, 2008 Does the switch that sits between the router and the switch that has the P.C on it have the VLAN that you want the P.C to be a member of PC--SWITCH(VLAN 3)-----SWITCH(VLAN3)-----ROUTER(VLAN3) The transit switch must host the VLAN that it you want to carry, even if there are no members of that vlan on that switch Make sure that the links on the HP that are being used as trunks are all members of the tagged vlan. Hope this helps
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now