Problem:
When you PING from a Source PC (10.1.200.18) to a destination a layer 2 switch in our example (10.1.100.1) it works fine, when this is connected to Standby Router (GE1/6/1) directly.
However when the same Source PC (10.1.200.18) connected to Master (GE2/6/1) it doesn’t work.
Now as these Routers are in IRF they should act as single identity and this should work flawlessly, irrespective of where the PC is being connected to which router, however in the MSR 3024 Router, it did not work as expected.
Let's see how to resolve this step by step below,
Setup Involves:
2 X MSR 3024 Routers
1 X Switch (Destination)
1 X PC (Source)
2 Different Broadcast Domain involved as shown in the diagram below :
Network diagram:
Diagnostics:Router Configurations:
<MARINA-POS-RTR>display irf
MemberID Role Priority CPU-Mac Description
+1 Standby 28 1075-df0f-0e04 ---
*2 Master 30 1075-e65a-0f04 ---
--------------------------------------------------
* indicates the device is the master.
+ indicates the device through which the user logs in.
The bridge MAC of the IRF is: 1075-e65a-0f00
Auto upgrade : yes
Mac persistent : 6 min
Domain ID : 0
Auto merge : yes
<MARINA-POS-RTR>display link-aggregation verbose Route-Aggregation 100
Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing
Port: A -- Auto
Port Status: S -- Selected, U -- Unselected, I -- Individual
Flags: A -- LACP_Activity, B -- LACP_Timeout, C -- Aggregation,
D -- Synchronization, E -- Collecting, F -- Distributing,
G -- Defaulted, H -- Expired
Aggregate Interface: Route-Aggregation100
Aggregation Mode: Dynamic
Loadsharing Type: Shar
System ID: 0x8000, 1075-e65a-0f00
Local:
Port Status Priority Oper-Key Flag
--------------------------------------------------------------------------------
GE1/5/1 S 32768 1 {ACDEF}
GE2/5/0 S 32768 1 {ACDEF}
Remote:
Actor Partner Priority Oper-Key SystemID Flag
--------------------------------------------------------------------------------
GE1/5/1 32 32768 1 0x8000, 1076-1099-1000 {ACDEF}
GE2/5/0 33 32768 1 0x8000, 1076-1099-1000 {ACDEF}
<MARINA-POS-RTR>display current-configuration interface Route-Aggregation 100
#
interface Route-Aggregation100
ip address 10.1.100.13 255.255.255.0
link-aggregation mode dynamic
#
Note : The Destination Switch with an IP address of 10.1.100.1/24 is connected to the above RAGG100.
<MARINA-POS-RTR>display IP interface brief
*down: administratively down
(s): spoofing (l): loopback
Interface Physical Protocol IP Address Description
GE1/0/0 down down -- --
GE1/5/0 down down -- --
GE1/5/1 up up -- --
GE2/0/0 down down -- --
GE2/5/0 up up -- --
GE2/6/0 down down -- --
RAGG100 up up 10.1.100.13 --
Ser1/1/0 down down -- --
Ser2/1/0 down down -- --
Vlan200 down down 10.1.200.50 --
<MARINA-POS-RTR>display current-configuration interface GigabitEthernet 1/6/1
#
interface GigabitEthernet1/6/1
port link-mode bridge
port access vlan 200
combo enable copper
<MARINA-POS-RTR>display current-configuration interface GigabitEthernet 2/6/1
#
interface GigabitEthernet2/6/1
port link-mode bridge
port access vlan 200
combo enable copper
Note : The Source PC with an IP address of 10.1.200.18/24 now is connected 2/6/1, however it would be moved to 1/6/1 to exemplify the PINGs results.
Switch Configuration:
<5820_Switch>display link-aggregation verbose Bridge-Aggregation 100
Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing
Port: A -- Auto
Port Status: S -- Selected, U -- Unselected, I -- Individual
Flags: A -- LACP_Activity, B -- LACP_Timeout, C -- Aggregation,
D -- Synchronization, E -- Collecting, F -- Distributing,
G -- Defaulted, H -- Expired
Aggregate Interface: Bridge-Aggregation100
Aggregation Mode: Dynamic
Loadsharing Type: Shar
System ID: 0x8000, 1076-1099-1000
Local:
Port Status Priority Oper-Key Flag
--------------------------------------------------------------------------------
GE1/0/31 S 32768 1 {ACDEF}
GE1/0/32 S 32768 1 {ACDEF}
Remote:
Actor Partner Priority Oper-Key SystemID Flag
--------------------------------------------------------------------------------
GE1/0/31 9 32768 1 0x8000, 1075-e65a-0f00 {ACDEF}
GE1/0/32 136 32768 1 0x8000, 1075-e65a-0f00 {ACDEF}
<5820_Switch>display current-configuration interface Bridge-Aggregation 100
#
interface Bridge-Aggregation100
port access vlan 100
link-aggregation mode dynamic
#
<5820_Switch>display ip interface brief
*down: administratively down
(s): spoofing (l): loopback
Interface Physical Protocol IP Address Description
MGE0/0/0 down down -- --
Vlan100 up up 10.1.100.1 --
Reach-ability issue :
When the Source PC (10.1.200.18/24) connected to interface Gig2/6/1 and when tried pinging the destination switch (10.1.100.1/24) you may see the RTOs,
However at the same time, when we moved the PC connection to Gig1/6/1, you can see the PC was able to reach the destination above.
SolutionYou have to configure the Router’s slots as service slot to pass the PING traffic.
Get in to the following layer 3 interfaces and configure them as 'service slots'
interface Route-Aggregation100
service slot 1
interface Vlan-interface200
service slot 1
Details :
The traffic processing unit can be a card on a distributed device or a member device on an IRF fabric of centralized devices.
For the specified unit to process traffic for the interface, make sure the unit is available.
Traffic on a Layer 3 aggregate interface is processed by the card or device at which it arrives if you do not specify traffic processing units for the interface.
For traffic on a layer 3 aggregate interface to be process on the same unit, you can perform one or both of the following tasks:
• Specify one primary traffic processing unit by using the service command.
• Specify one backup traffic processing unit by using the service standby command.
The backup unit takes over when the primary unit becomes unavailable. The backup unit continues to process traffic for the interface after the primary unit becomes available again.
The switchover will not occur until the backup unit becomes unavailable.
If both primary and backup units are unavailable, the traffic will be dropped.
If the aggregate interface contains subinterfaces, ingress traffic on the subinterfaces is also processed by the specified traffic processing unit.