03-12-2010 05:20 AM - edited 03-06-2019 10:06 AM
Hello
I am a network newbie so be gentle - can somebody help me with what I think is a trivial problem. I have 2 switches (Cisco 3020) linked together via an uplink port and a number of servers (blades in this case) attached. On each server/blade Nic0 is physically attached to Switch0 and Nic1 is physically attached to Switch1.
Network communication between all servers is ok as long as i hit the correct network card via the correct switch.. Eg from 10.10.11.203 if i hit a nic that is physically attached, it all works fine. It is when i want to send traffic across the switches i have issues. For example if i send traffic from 10.10.11.203 to 10.10.11.16 the traffic does not traverse switches via gi0/24, instead it insists on using gi0/19 which is attached to a switch (not uplinked) on another network which fails.
I need to somehow configure the switch(es) so that Switch 0 always attempts to use Switch 1 via the uplink before finally the decision is made to send traffic upwards over gi0/19 and onwards to other switches on the network.
Any help whatsoever is very much appreciated.
(1) Traceroute from (SW0) with SW1-gi0/19 enabled running traceroute from 10.10.11.203 to 10.10.11.16
Translating IP to mac .....
10.10.11.203 => 0022.649e.3ec6
10.10.11.16 => 0022.649b.dce2
Source 0022.649e.3ec6 found on SW0
1 SW0 (10.10.11.30) : Gi0/17 => Gi0/19
Unable to send a l2trace request to 192.168.20.5. Timed out
Layer2 trace aborted.
(2) Traceroute from (SW0) with SW1-gi0/19 enabled running traceroute from 10.10.11.203 to 10.10.11.116
Translating IP to mac .....
10.10.11.203 => 0022.649e.3ec6
10.10.11.116 => 0022.649b.dce4
Source 0022.649e.3ec6 found on SW0
1 SW0 (10.10.11.30) : Gi0/17 => Gi0/16
Destination 0022.649b.dce4 found on SW0
Layer2 trace completed.
(3) Traceroute from (SW1) with SW1-gi0/19 enabled running traceroute from 10.10.11.203 to 10.10.11.16
Translating IP to mac .....
10.10.11.203 => 0022.649e.3ec6
10.10.11.16 => 0022.649b.dce2
Unable to send a l2trace request to 192.168.20.5. Timed out
Layer2 trace aborted.
(4) Traceroute from (SW1) with SW1-gi0/19 enabled running traceroute from 10.10.11.203 to 10.10.11.116
Translating IP to mac .....
10.10.11.203 => 0022.649e.3ec6
10.10.11.116 => 0022.649b.dce4
Unable to send a l2trace request to 192.168.20.5. Timed out
Layer2 trace aborted.
(5) Traceroute from (SW0) with SW1-gi0/19 disabled running traceroute from 10.10.11.203 to 10.10.11.16
Translating IP to mac .....
10.10.11.203 => 0022.649e.3ec6
10.10.11.16 => 0022.649b.dce2
Source 0022.649e.3ec6 found on SW0
1 SW0 (10.10.11.30) : Gi0/17 => Gi0/24
2 SW1 (10.10.11.31) : Gi0/24 => Gi0/16
Destination 0022.649b.dce2 found on SW1
Layer 2 trace completed
(6) Traceroute from (SW0) with SW1-gi0/19 disabled running traceroute from 10.10.11.203 to 10.10.11.116
Translating IP to mac .....
10.10.11.203 => 0022.649e.3ec6
10.10.11.116 => 0022.649b.dce4
Source 0022.649e.3ec6 found on SW0
1 SW0 (10.10.11.30) : Gi0/17 => Gi0/16
Destination 0022.649b.dce4 found on SW0
Layer2 trace completed.
(7) Traceroute from (SW1) with SW1-gi0/19 disabled running traceroute from 10.10.11.203 to 10.10.11.116
Translating IP to mac .....
10.10.11.203 => 0022.649e.3ec6
10.10.11.16 => 0022.649b.dce2
Source 0022.649e.3ec6 found on SW0
1 SW0 (10.10.11.30) : Gi0/17 => Gi0/24
2 SW1 (10.10.11.31) : Gi0/24 => Gi0/16
Destination 0022.649b.dce2 found on SW1
Layer 2 trace completed
(8) Traceroute from (SW1) with SW1-gi0/19 disabled running traceroute from 10.10.11.203 to 10.10.11.116
Translating IP to mac .....
10.10.11.203 => 0022.649e.3ec6
10.10.11.116 => 0022.649b.dce4
Source 0022.649e.3ec6 found on SW0
1 SW0 (10.10.11.30) : Gi0/17 => Gi0/16
Destination 0022.649b.dce4 found on SW0
Layer 2 trace completed
Switch 0 Running Config
!
version 12.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
service sequence-numbers
!
hostname SW0
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$kDjk$GQ9ITEuCUwhGVFptPE2t9/
!
!
!
no aaa new-model
system mtu routing 1500
authentication mac-move permit
ip subnet-zero
!
!
!
!
!
!
!
spanning-tree mode pvst
spanning-tree etherchannel guard misconfig
spanning-tree extend system-id
spanning-tree uplinkfast
!
vlan internal allocation policy ascending
!
ip tftp source-interface FastEthernet0
!
!
interface FastEthernet0
ip address dhcp
!
interface GigabitEthernet0/1
spanning-tree portfast
!
interface GigabitEthernet0/2
spanning-tree portfast
!
interface GigabitEthernet0/3
spanning-tree portfast
!
interface GigabitEthernet0/4
spanning-tree portfast
!
interface GigabitEthernet0/5
spanning-tree portfast
!
interface GigabitEthernet0/6
spanning-tree portfast
!
interface GigabitEthernet0/7
spanning-tree portfast
!
interface GigabitEthernet0/8
spanning-tree portfast
!
interface GigabitEthernet0/9
spanning-tree portfast
!
interface GigabitEthernet0/10
spanning-tree portfast
!
interface GigabitEthernet0/11
spanning-tree portfast
!
interface GigabitEthernet0/12
spanning-tree portfast
!
interface GigabitEthernet0/13
spanning-tree portfast
!
interface GigabitEthernet0/14
spanning-tree portfast
!
interface GigabitEthernet0/15
spanning-tree portfast
!
interface GigabitEthernet0/16
spanning-tree portfast
!
interface GigabitEthernet0/17
description G5 Uplink
spanning-tree portfast trunk
!
interface GigabitEthernet0/18
!
interface GigabitEthernet0/19
description Dev Network Uplink
media-type rj45
!
interface GigabitEthernet0/20
!
interface GigabitEthernet0/21
!
interface GigabitEthernet0/22
!
interface GigabitEthernet0/23
!
interface GigabitEthernet0/24
description X-Uplink Port
media-type internal
!
interface Vlan1
ip address 10.10.11.30 255.255.255.0
!
ip classless
ip http server
!
ip sla enable reaction-alerts
!
line con 0
line vty 0 4
password Passw0rd123
login
line vty 5 15
password Passw0rd123
login
!
end
Switch 1 Running Config
!
version 12.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
service sequence-numbers
!
hostname SW1
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$XR9L$VATn0pC6x/SxtOrhv1frA0
!
!
!
no aaa new-model
system mtu routing 1500
authentication mac-move permit
ip subnet-zero
!
!
!
!
!
!
spanning-tree mode pvst
spanning-tree etherchannel guard misconfig
spanning-tree extend system-id
!
vlan internal allocation policy ascending
!
!
!
interface FastEthernet0
ip address dhcp
!
interface GigabitEthernet0/1
spanning-tree portfast
!
interface GigabitEthernet0/2
spanning-tree portfast
!
interface GigabitEthernet0/3
spanning-tree portfast
!
interface GigabitEthernet0/4
spanning-tree portfast
!
interface GigabitEthernet0/5
spanning-tree portfast
!
interface GigabitEthernet0/6
spanning-tree portfast
!
interface GigabitEthernet0/7
spanning-tree portfast
!
interface GigabitEthernet0/8
spanning-tree portfast
!
interface GigabitEthernet0/9
spanning-tree portfast
!
interface GigabitEthernet0/10
spanning-tree portfast
!
interface GigabitEthernet0/11
spanning-tree portfast
!
interface GigabitEthernet0/12
spanning-tree portfast
!
interface GigabitEthernet0/13
spanning-tree portfast
!
interface GigabitEthernet0/14
spanning-tree portfast
!
interface GigabitEthernet0/15
spanning-tree portfast
!
interface GigabitEthernet0/16
spanning-tree portfast
!
interface GigabitEthernet0/17
!
interface GigabitEthernet0/18
!
interface GigabitEthernet0/19
description Dev Network Uplink
shutdown
media-type rj45
!
interface GigabitEthernet0/20
!
interface GigabitEthernet0/21
!
interface GigabitEthernet0/22
!
interface GigabitEthernet0/23
!
interface GigabitEthernet0/24
description X-Uplink Port
media-type internal
!
interface Vlan1
ip address 10.10.11.31 255.255.255.0
!
ip classless
ip http server
!
ip sla enable reaction-alerts
!
line con 0
line vty 0 4
password Passw0rd123
login
line vty 5 15
password Passw0rd123
login
!
end
03-12-2010 07:35 AM
Steve,
I havent had a chance to fully read the configs and traces you posted, so apologies if my answer is incorrect, however it sounds to me asthough there are 3 switches in the network, the 2 x 3020 and the upstream switch (attached to gig0/19).
Spanning tree may have put the link between the 2 x 3020 in to block to avoid any switching loops, therefore traffic will go via gig0/19.
Please run show 'spanning tree blockedports' on the 2 x 3020 to see if this is the case, if so you can adjust the STP config according.
Kind regards
Steve
03-12-2010 08:21 AM
Many many thanks for this heads up..
Running ... the following commands - i got this information...
I have no idea if its relevant, however i see that gi0/19 has a cost of 23 for SW1 and 3023 for SW0
Does this shed any light -- sorry for my total lack of knowledge on this ....
SW0#show spanning-tree
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 32768
Address 0007.85e7.2f00
Cost 3023
Port 19 (GigabitEthernet0/19)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 49153 (priority 49152 sys-id-ext 1)
Address 0023.05dd.5d00
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec
Uplinkfast enabled
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/1 Desg FWD 3004 128.1 P2p Edge
Gi0/2 Desg FWD 3004 128.2 P2p Edge
Gi0/3 Desg FWD 3004 128.3 P2p Edge
Gi0/4 Desg FWD 3004 128.4 P2p Edge
Gi0/5 Desg FWD 3004 128.5 P2p Edge
Gi0/6 Desg FWD 3004 128.6 P2p Edge
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/7 Desg FWD 3004 128.7 P2p Edge
Gi0/8 Desg FWD 3004 128.8 P2p Edge
Gi0/9 Desg FWD 3004 128.9 P2p Edge
Gi0/10 Desg FWD 3004 128.10 P2p Edge
Gi0/11 Desg FWD 3004 128.11 P2p Edge
Gi0/12 Desg FWD 3004 128.12 P2p Edge
Gi0/13 Desg FWD 3004 128.13 P2p Edge
Gi0/14 Desg FWD 3004 128.14 P2p Edge
Gi0/15 Desg FWD 3004 128.15 P2p Edge
Gi0/16 Desg FWD 3004 128.16 P2p Edge
Gi0/17 Desg FWD 3004 128.17 P2p Edge
Gi0/19 Root FWD 3019 128.19 Shr
Gi0/24 Desg FWD 3004 128.24 P2p
SW0#show spanning-tree blockedports
Name Blocked Interfaces List
-------------------- ------------------------------------
Number of blocked ports (segments) in the system : 0
SW0#sh span root
Root Hello Max Fwd
Vlan Root ID Cost Time Age Dly Root Port
---------------- -------------------- --------- ----- --- --- ------------
VLAN0001 32768 0007.85e7.2f00 3023 2 20 15 Gi0/19
And on Switch 1
SW1#show spanning-tree
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 32768
Address 0007.85e7.2f00
Cost 23
Port 19 (GigabitEthernet0/19)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 0023.05dd.3880
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/1 Desg FWD 4 128.1 P2p Edge
Gi0/2 Desg FWD 4 128.2 P2p Edge
Gi0/3 Desg FWD 4 128.3 P2p Edge
Gi0/4 Desg FWD 4 128.4 P2p Edge
Gi0/5 Desg FWD 4 128.5 P2p Edge
Gi0/6 Desg FWD 4 128.6 P2p Edge
Gi0/7 Desg FWD 4 128.7 P2p Edge
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/8 Desg FWD 4 128.8 P2p Edge
Gi0/9 Desg FWD 4 128.9 P2p Edge
Gi0/10 Desg FWD 4 128.10 P2p Edge
Gi0/11 Desg FWD 4 128.11 P2p Edge
Gi0/12 Desg FWD 4 128.12 P2p Edge
Gi0/13 Desg FWD 4 128.13 P2p Edge
Gi0/14 Desg FWD 4 128.14 P2p Edge
Gi0/15 Desg FWD 4 128.15 P2p Edge
Gi0/16 Desg FWD 4 128.16 P2p Edge
Gi0/19 Root FWD 19 128.19 Shr
Gi0/24 Desg FWD 4 128.24 P2p
SW1#show spanning-tree blockedports
Name Blocked Interfaces List
-------------------- ------------------------------------
Number of blocked ports (segments) in the system : 0
SW1#sh span root
Root Hello Max Fwd
Vlan Root ID Cost Time Age Dly Root Port
---------------- -------------------- --------- ----- --- --- ------------
VLAN0001 32768 0007.85e7.2f00 23 2 20 15 Gi0/19
03-12-2010 03:50 PM
Hi Steve,
I haven't read through the config, but whenever i see a port cost above 3000 i think uplinkfast. Have you got uplinkfast enabled on one of the switches?
Thanks,
Jason.
03-15-2010 04:36 AM
Yes portfast is enabled on the switch
Should it be??
I thought portfast just allowed the switch to fail over via the uplink quickly.
Also i notice that on SW0 gi0/24 has the "orange" disabled light on ...is this relevant...i assume it should be "enabled" I have not disabled it, it seems to "disable" itself automatically.
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