06-14-2006 02:43 AM - edited 03-03-2019 03:38 AM
i have a VPN tunnel between two of our offices. The links are provided by two service providers .Both links are 45 Mbps ethernet hands off. I have created ether channel between the two links.The connection is like
PIX ---- L3 switch1---Service providers----switch2----- PIX2. Port channel is working fine as a 90 Mbps link. But i can see in my MRTG that always one link is in use . other link trafic is in mere Kbps. Switch port channel config is as follows:
Switch 1:
vlan 10
name MAN_CONNECTION
!
!
interface Port-channel10
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
!
!
interface FastEthernet1/0/2
description "TTSL"
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
load-interval 30
duplex full
speed 100
channel-group 10 mode desirable non-silent
!
interface FastEthernet1/0/3
description "Airtel"
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
load-interval 30
duplex full
speed 100
channel-group 10 mode desirable non-silent
Switch 2:
vlan 10
name MAN_CONNECTION
!
!
interface Port-channel1
!
interface Port-channel10
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
logging event bundle-status
!
!
interface FastEthernet1/0/2
description "TTSL"
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
load-interval 30
duplex full
speed 100
channel-group 10 mode desirable non-silent
!
interface FastEthernet1/0/3
description "Airtel"
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
load-interval 30
duplex full
speed 100
channel-group 10 mode desirable non-silent
Can some body give a clue ,why only one link is loaded. both the links are 45 MBps.
Thank you
Ullas Upendran
06-14-2006 03:21 AM
Load sharing is based on L2 information.
source address is PIX1
destination address is PIX2
XOR load-balances on this information. Because the source/destination address is the same for all frames no real load-balancing is performed.
http://www.cisco.com/en/US/tech/tk389/tk213/technologies_tech_note09186a0080094714.shtml
--Leon
06-14-2006 04:39 AM
Thanks leon. But the switch i have on both sides are Layer 3 and is doing routing also .
the full switch config is as follows.
hostname MAN-Ulsoor-3750
!
aaa new-model
aaa authentication login default group tacacs+ local
aaa authentication enable default group tacacs+ enable
aaa accounting exec default start-stop group tacacs+
aaa accounting commands 1 default start-stop group tacacs+
aaa accounting commands 15 default start-stop group tacacs+
ip routing
!
vtp domain PIC
vtp mode transparent
!
spanning-tree mode pvst
no spanning-tree optimize bpdu transmission
spanning-tree extend system-id
!
!
vlan 10
name MAN_CONNECTION
!
!
interface Port-channel1
!
interface Port-channel10
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
logging event bundle-status
!
interface FastEthernet1/0/1
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
shutdown
!
interface FastEthernet1/0/2
description "TTSL"
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
load-interval 30
duplex full
speed 100
channel-group 10 mode desirable non-silent
!
interface FastEthernet1/0/3
description "Airtel"
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport mode trunk
load-interval 30
duplex full
speed 100
channel-group 10 mode desirable non-silent
!
interface FastEthernet1/0/23
description *** PIX-Ulsoor Standby ***
duplex full
speed 100
!
interface FastEthernet1/0/24
description *** PIX-Ulsoor Active ***
duplex full
speed 100
!
interface GigabitEthernet1/0/1
!
interface GigabitEthernet1/0/2
!
interface GigabitEthernet1/1/1
!
interface GigabitEthernet1/1/2
!
interface Vlan1
ip address 10.253.253.27 255.255.255.248
!
interface Vlan10
ip address 10.253.253.18 255.255.255.248
!
ip default-gateway 10.253.253.25
ip classless
ip route 0.0.0.0 0.0.0.0 10.253.253.25
ip route 10.253.253.0 255.255.255.248 10.253.253.17
ip route 10.253.253.8 255.255.255.248 10.253.253.17
ip route 161.85.28.0 255.255.254.0 10.253.253.17
ip route 161.85.97.0 255.255.255.0 10.253.253.17
ip route 161.85.99.0 255.255.255.0 10.253.253.17
ip route 161.85.102.0 255.255.255.0 10.253.253.17
ip route 161.85.103.0 255.255.255.0 10.253.253.17
no ip http server
ip tacacs source-interface Vlan1
!
Even if the sourse ip is of the switch ,load balancing is not possible? As my second link is always idle ,is there any way i can utilise it?
Thanks
Ullas
06-14-2006 04:53 AM
ullas,
i think actully load balancing work lik this...
Load distribution is based on the source-MAC address of the incoming packet. Packets from different hosts use different ports in the channel, but packets from the same host use the same port in the channel.
When src-mac is used, load distribution based on the source and destination IP address is also enabled. For all IP traffic being routed, the switch chooses a port for transmission based on the source and destination IP address. Packets between two IP hosts always use the same port for packet transmission, but packets between any other pair of hosts might use a different transmission port.
Load distribution is based on the destination-host MAC address of the incoming packet. Packets to the same destination are sent on the same port, but packets to different destinations are sent on different ports in the channel.
may this will help you in configuration...
rate this post if it helps
regards
Devang
06-14-2006 04:55 AM
Hi,
This command is suppose to allow for source and destination IP loadbalancing on a etherchannel.
Router(config)#port-channel load-balance src-dst-ip
Use
Router# show etherchannel load-balance
to view what type loadbalancing is in use.
Richard
06-14-2006 08:47 PM
hi richard
the out put shows
MAN-Ulsoor-3750#sh etherchannel load-balance
Source MAC address
MAN-Ulsoor-3750#
thanks ullas
06-14-2006 04:57 AM
Please refer to the documentation of your 3750 switch. See the Etherchannel documentation on Load Balancing:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3750/12225see/scg/swethchl.htm#wp1275731
The problem is that you have a static source/destination which makes load-balancing accross an etherchannel difficult.
--Leon
06-15-2006 12:47 AM
Hi all
i configured etherchannel load balancing with source ip on both the switches . Now i can see the traffic is evenly going in both the links.Thanks a lot
Ullas
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