| Author |
InterVlan Routing and ISL Trunking
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| ttwtang 2002-09-13, 3:28 am |
| Dear all,
Could any one solve this?
I have a Cisco 2620 (one Ethernet and one Serial), and a Cat 2950.
Cat 2950 is layer 2, I created 4 Vlans, and a trunking port, which is connected to the Cisco 2620. So, the two machines add up equal to a layer 3 switch.
For Cisco 2950, it only supports 802.1q. So, I use it.
For Cisco 2620, I created sub-interface for each Vlan. Hope you all understand.
The problem is: Seems like my router is very heavy loaded. Even the traffic is low.
Ping test shown are not consistant.
Can anyone help?
Send me email: tingweetang@clearcomm.com.my | |
| darthfeces 2002-09-13, 9:06 am |
| your're not very clear here ?
3 things a router should never exhaust
cpu cycles
bandwidth
memory
do some detective work
there are document on cisco's site related to heavy load
how much ram in your router ?
try some dubugs
sh ver
sh proc mem
sh log | |
| jburch 2002-09-13, 12:24 pm |
| I seen in the book "When performance on the vlan is slow or unrealiable, possible causes is:
Bad adapter in a device. Check hardware.
Full-duplex or half-duplex Ethernet settings incorrect.
Cabling problem. Check connected LED. Check for correct cable properly attached and if lenght exceeds maximum cable distant.
I know some of it doesn't apply, but I was on that page in the book pg. 462 when I read this thread. Thought it might help.
Chapter 11: Troubleshooting VLANs on Routers and Switches.
Cisco Press CIT | |
| Yankee 2002-09-14, 5:24 am |
| I have seen sites where all they have is two IP blocks (one is a secondary) on the same fastethernet interface. The network tech there did some sort of huge backup between two hosts. You guessed it... the idiot had one host on each IP block so the router had to route each packet. This was a 2621 and its CPU was constantly at 80% or higher.
I suspect there may be something similar on your network... lots of routing between VLANs.
Yankee | |
| ttwtang 2002-09-15, 7:38 pm |
| For the Cisco 2620, I only do routing for the default route, which is point to the Serial.
Here is the configuration, I've marked out the IP address here.
interface FastEthernet0/0
no ip address
speed 100
full-duplex
!
interface FastEthernet0/0.1
description Portal
encapsulation dot1Q 1 native
ip address x.x.x.x y.y.y.y
!
interface FastEthernet0/0.2
bandwidth 2048
encapsulation dot1Q 2
ip address
!
interface FastEthernet0/0.3
bandwidth 512
encapsulation dot1Q 3
ip address x.x.x.x y.y.y.y
!
interface FastEthernet0/0.4
encapsulation dot1Q 6
ip address x.x.x.x y.y.y.y
!
interface FastEthernet0/0.5
bandwidth 256
encapsulation dot1Q 7
ip address x.x.x.x y.y.y.y
shutdown
!
interface FastEthernet0/0.6
bandwidth 2048
encapsulation dot1Q 5
shutdown
!
interface Serial0/0
ip address x.x.x.x y.y.y.y
no fair-queue
!
ip classless
ip route 0.0.0.0 0.0.0.0 Serial0/0
ip http server
!
!
!
snmp-server community public RO
snmp-server enable traps tty
call rsvp-sync
!
!
mgcp profile default
!
dial-peer cor custom
!
For Cisco 2950:
interface FastEthernet0/1
switchport trunk allowed vlan 1-7, 1002-1005
switchport mode trunk
duplex full
speed 100
!
interface FastEthernet0/2
spanning-tree portfast
!
interface FastEthernet0/3
spanning-tree portfast
!
interface FastEthernet0/4
!
interface FastEthernet0/5
!
interface FastEthernet0/6
!
interface FastEthernet0/7
!
interface FastEthernet0/8
!
interface FastEthernet0/9
switchport access vlan 2
spanning-tree portfast
!
interface FastEthernet0/10
switchport access vlan 2
spanning-tree portfast
!
interface FastEthernet0/11
switchport access vlan 3
spanning-tree portfast
!
interface FastEthernet0/12
switchport access vlan 3
spanning-tree portfast
!
interface FastEthernet0/13
switchport access vlan 7
spanning-tree portfast
!
interface FastEthernet0/14
switchport access vlan 7
spanning-tree portfast
!
interface FastEthernet0/15
switchport access vlan 4
spanning-tree portfast
!
interface FastEthernet0/16
switchport access vlan 4
spanning-tree portfast
!
interface FastEthernet0/17
switchport access vlan 6
spanning-tree portfast
!
interface FastEthernet0/18
switchport access vlan 6
spanning-tree portfast
!
interface FastEthernet0/19
!
interface FastEthernet0/20
!
interface FastEthernet0/21
!
interface FastEthernet0/22
!
interface FastEthernet0/23
switchport access vlan 8
!
interface FastEthernet0/24
switchport access vlan 8
!
interface Vlan1
ip address x.x.x.x y.y.y.y
no ip route-cache
I know this is "digusting", I'll appreciate if you help.
Thanks. | |
| edmonds_robert 2002-09-19, 1:51 pm |
| I know you have only added the one route statically (ip route 0.0.0.0), but you are still routing every packet that traverses VLANs since they are on different subnets. You can't switch between IP subnets (at least not a layer 2).
I think the problem is you just have too much traffic for the configuration you have. I would consult with Cisco and consider an equipment upgrade, possibly to the 3550 series switch with the EMI image. | |
| Yankee 2002-09-20, 2:45 am |
| Don't believe new equipment is the answer. A better LAN design would be more appropriate for the exact reasons already given.
Yankee | |
| edmonds_robert 2002-09-20, 7:51 am |
| I wasn't suggesting that anybody rush out and upgrade their network. I said "Consult with Cisco" first. They will be able to isolate your problem and tell you the best route. Either way, I would call them.k It has been my experience that their tech support is excellent. And if the person you are talking to can't answer your question, they will either find out and get back to you or get you in touch with someone who can. | |
| Yankee 2002-09-21, 5:14 am |
| Yep, TAC can be very helpful but my point is that I believe the problem has already been exposed and all he has to do is correct it.
Yankee | |
| subnet__zero 2002-09-21, 3:10 pm |
| Well said, Yankee!
I thought that you were dead on in your post on 9/14/02 and that the thread originator should have went back to and re-examined his objectives and came up with a redesign. Maybe a better understanding of the purpose behind creating VLANs would be helpfull for ttwtang as well. |
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