I have a problem and i don't know how i can solve that. Hope someone of you can give me some input.
In a Network with 300 clients, i want to make different subnets with one dhcp server. in theory just activate IP Helper-Address an it works. But the problem is, i have only a switch and not a router. I would set for every subnet a different vlan, so i can map the vlan on the interface (can't set a ip for ip helper on the physical interface because its a switch..) and activate ip helper address on the vlan interface.
But now i have a problem with the routing. The coreswitch have now 2 vlans, vlan 1 (10.12.100.1) and vlan 2 (10.12.40.1). the default route is set to 10.12.100.10 (Cable-switch from the provider). The client (10.12.40.2) can ping every ip in the 100 subnet.. i can ping the server 10.12.100.101, but i can not ping the cablerouter 10.12.100.10.. i can ping every device, just not the cablerouter...
here the config from the core-switch:
Current configuration : 4328 bytes
! Last configuration change at 10:55:56 CET Wed Oct 14 2009
! NVRAM config last updated at 16:01:19 CET Tue Oct 13 2009
no service pad
service timestamps debug datetime localtime
service timestamps log datetime localtime
no aaa new-model
clock timezone CET 1
clock summer-time CET recurring last Sun Mar 2:00 last Sun Oct 3:00
switch 1 provision ws-c3750g-12s
switch 2 provision ws-c3750g-12s
system mtu routing 1500
no ip domain-lookup
ip domain-name dnata.intra
cluster enable dnata 0
cluster member 1 mac-address 001e.7a91.d980
cluster member 2 mac-address 001e.f659.1e80
cluster member 3 mac-address 001e.f629.3180
cluster member 4 mac-address 001e.79c3.cb00
cluster member 5 mac-address 001d.e676.5b80
cluster member 6 mac-address 001d.e675.fe00
cluster member 7 mac-address 001d.e698.f780
cluster member 8 mac-address 001d.e699.0d80
cluster member 9 mac-address 001d.e698.c380
cluster member 10 mac-address 001d.e699.6700
cluster member 11 mac-address 001d.e698.ee00
cluster member 12 mac-address 001d.e699.0180
cluster member 13 mac-address 001d.e675.ee00
cluster member 14 mac-address 001e.49eb.0a80
no file verify auto
spanning-tree mode pvst
spanning-tree extend system-id
vlan internal allocation policy ascending
description to sw_s33
description to sw_gh
description to sw_lost
description to sw_transit
description to sw_assist
description to sw_4thfloor
switchport access vlan 2
ip address 10.12.100.1 255.255.255.0
ip address 10.12.40.1 255.255.255.0
ip route 0.0.0.0 0.0.0.0 10.12.100.10
ip http server
**some snmp settings**
line con 0
line vty 0 4
line vty 5 15
The switch was first configurated from a external company who has delivered us the switches..
have someone an idea what the problem is? Thx for your help.
Check your route on your cable router to make sure it has a return route to the 10.12.40.0/255.255.255.0 network.
If it is IOS, you can use
ip route 10.12.40.0 255.255.255.0 10.12.100.1
the problem is, i haven't access to the cablerouter, because its the router from the internetprovider. :(
But i have testet the subnet 40, if i set the ip address in the default vlan 1 (the port and the client) i can ping the router from the client with the ip address 10.12.40.2. so it must be a problem on the core switch with routing from vlan 1 and 2, right? but then its strange that the ping to all other clients works...
or is it wrong?
Please explain a little further. I don't understand what you have tested, do you mean you've put the switchport into VLAN1 but the client/PC's IP is still 10.12.40.x, and ping works fine?
ICMP echo is coming from the client to the cable router, and the cable router will send echo reply (return route). If the route on the cable router is missing, I don't see how the traffic will return.
thanks for your answers jerry
I have put the port on the switch and the computer in the vlan 1, but with the ip from the 40 subnet.
on the vlan 1 interface on the switch with the ip 10.12.100.1 i have added the ip 10.12.40.1 as secondary. then the ping works from the computer with the ip 10.12.40.2... but its on vlan 1, not in 2...
thanks for the answers
but when the client is in the vlan 1 with the same ip, it can ping the router..
my problem is not that the ping not works, the connection to the other location over the isp don't works too, but only from the clients in the vlan2.
A bit confused. But are you saying that you cannot ping the cable router (.10) from any device on vlan1 or vlan2? What does your interface look like that is connected to the cable router?
i.e. show interface gig1/0
replace gig1/0 with the physical interface connected to your cable router. Just to make sure you don't have any layer 2 issues.