RSMLT Redundancy of ERS8600

Posted On Feb 13, 2009 at at 5:50 PM by Dophi  

    As a core switch in a network, ERS8600 provides both L2 and L3 active-active redundancy via Split Multi-Link Trunk (SMLT) and extended VRRP (VRRP Backup Master). In some cases,  the VRRP instances might be used over 255 or routing protocols’ convergence time is too long to recover network traffic shortly. Routed Split Multi-Link Trunk (RSMLT) is designed to perform rapid routing failover for core topologies.  It cooperates with SMLT and extends it to achieve active-active L3 routing. In other words, the limitation of VRRP instance and long failover convergence no longer exist.


    The topology below is a simple L2 edge RSMLT triangle clustering example and I would like to use this topology to make a configuration note.

Software : ERS8600 version 5.0.0.1; ERS5500 version 5.1.1

RSMLT

 

1. Create VLAN 2 and 3 on ERS8600 A:  Assign port 2/47-2/48 as members of VLAN 2 and 2/35-2/36 as members of VLAN 3.  Create IP address for VLAN 1, 2, and 3.

ERS-8606:5# config vlan 1 ip create 10.1.1.252/8
ERS-8606:5# config vlan 2 create byport 1
ERS-8606:5# config vlan 2 ports add 2/47-2/48
ERS-8606:5# config vlan 2 ip create 20.1.1.252/8
ERS-8606:5# config vlan 3 create byport 1
ERS-8606:5# config vlan 3 ports add 2/35-2/36
ERS-8606:5# config vlan 3 ip create 30.1.1.252/8

 

2 Create VLAN 2 and 3 on ERS8600 B:  Repeat the same procedures of ERS8600 A.

ERS-8606:5# config vlan 1 ip create 10.1.1.253/8
ERS-8606:5# config vlan 2 create byport 1
ERS-8606:5# config vlan 2 ports add 2/47-2/48
ERS-8606:5# config vlan 2 ip create 20.1.1.253/8
ERS-8606:5# config vlan 3 create byport 1
ERS-8606:5# config vlan 3 ports add 2/35-2/36
ERS-8606:5# config vlan 3 ip create 30.1.1.253/8

3. Create SMLT on ERS8600 A: VLAN 3 is used for IST trunk and we should assign a peer IP for it.

ERS-8606:5# config mlt 1 create
ERS-8606:5# config mlt 1 add ports 2/1
ERS-8606:5# config mlt 1 smlt create smlt-id 1
ERS-8606:5# config mlt 2 create
ERS-8606:5# config mlt 2 add ports 2/47
ERS-8606:5# config mlt 2 smlt create smlt-id 2
ERS-8606:5# config mlt 3 create
ERS-8606:5# config mlt 3 add ports 2/35-2/36
ERS-8606:5# config mlt 3 name "ist"
ERS-8606:5# config mlt 3 perform-tagging enable
ERS-8606:5# config mlt 3 ist create ip 30.1.1.253 vlan-id 3
ERS-8606:5# config mlt 3 ist enable
ERS-8606:5# config vlan 1 add-mlt 1
ERS-8606:5# config vlan 1 add-mlt 3
ERS-8606:5# config vlan 2 add-mlt 2
ERS-8606:5# config vlan 2 add-mlt 3
ERS-8606:5# config vlan 3 add-mlt 3

4. Create SMLT on ERS8600 B: Repeast the same procedures but assign the IP address of VLAN 3 of ERS8600 A as a peer IP.

ERS-8606:5# config mlt 1 create
ERS-8606:5# config mlt 1 add ports 2/1
ERS-8606:5# config mlt 1 smlt create smlt-id 1
ERS-8606:5# config mlt 2 create
ERS-8606:5# config mlt 2 add ports 2/47
ERS-8606:5# config mlt 2 smlt create smlt-id 2
ERS-8606:5# config mlt 3 create
ERS-8606:5# config mlt 3 add ports 2/35-2/36
ERS-8606:5# config mlt 3 name "ist"
ERS-8606:5# config mlt 3 perform-tagging enable
ERS-8606:5# config mlt 3 ist create ip 30.1.1.252 vlan-id 3
ERS-8606:5# config mlt 3 ist enable
ERS-8606:5# config vlan 1 add-mlt 1
ERS-8606:5# config vlan 1 add-mlt 3
ERS-8606:5# config vlan 2 add-mlt 2
ERS-8606:5# config vlan 2 add-mlt 3
ERS-8606:5# config vlan 3 add-mlt 3

5. Enable Global RSMLT Edge Support on ERS8600 A and B: This step lets ERS8600 store the RSMLT peer MAC/IP address pair in its local configuration file and restores the configuration if the peer does not restore after a simultaneous reboot of both RSMLT peer switches.

ERS-8606:5# config ip rsmlt rsmlt-edge-support enable

6. Enable RSMLT on each VLAN except VLAN 3 : This should be done on ERS8600 A and B.

ERS-8606:5# config vlan 1 ip rsmlt enable
ERS-8606:5# config vlan 2 ip rsmlt enable

7. Create MLT’s on ERS5500’s:

5520-24T-PWR(config)#mlt 1 member 1-2  
5520-24T-PWR(config)#mlt 1 enable
5520-24T-PWR(config)#mlt 1 loadbalance advance

 

Well, after those pretty simple steps, RSMLT has been created on ERS8600 A and B. Let’s verify the RSMLT on them.

RSMLT on ERS8600 A: ERS8600 A learns peer IP/MAC addresses automatically and save them in the configuration file. 

ERS-8606:5/show/ip/rsmlt# info

================================================================================
                       Ip Rsmlt Local Info - GlobalRouter
================================================================================

VID   IP              MAC                ADMIN   OPER  HDTMR  HUTMR  
--------------------------------------------------------------------------------
1     10.1.1.252      00:0c:f7:ea:d2:00  Enable  Up    60     180    
2     20.1.1.252      00:0c:f7:ea:d2:01  Enable  Up    60     180    

VID   SMLT ID                               SLT ID                         
--------------------------------------------------------------------------------
1       1                                                                   
2       2                                                                   

================================================================================
                       Ip Rsmlt Peer Info - GlobalRouter
================================================================================

VID   IP              MAC                ADMIN   OPER  HDTMR  HUTMR  
--------------------------------------------------------------------------------
1     10.1.1.253      00:0e:c0:32:e2:00  Enable  Up    60     180    

2     20.1.1.253      00:0e:c0:32:e2:01  Enable  Up    60     180    

VID   HDT REMAIN  HUT REMAIN  SMLT ID                               SLT ID                         
--------------------------------------------------------------------------------
1     60          180          1                                                                   
2     60          180          2                                         

RSMLT on ERS8600 B: ERS8600 B learns peer IP/MAC addresses automatically and save them in the configuration file.

ERS-8606:5# show ip rsmlt info

================================================================================
                       Ip Rsmlt Local Info - GlobalRouter
================================================================================

VID   IP              MAC                ADMIN   OPER  HDTMR  HUTMR  
--------------------------------------------------------------------------------
1     10.1.1.253      00:0e:c0:32:e2:00  Enable  Up    60     180    
2     20.1.1.253      00:0e:c0:32:e2:01  Enable  Up    60     180    

VID   SMLT ID                               SLT ID                         
--------------------------------------------------------------------------------
1       1                                                                   
2       2                                                                   

================================================================================
                       Ip Rsmlt Peer Info - GlobalRouter
================================================================================

VID   IP              MAC                ADMIN   OPER  HDTMR  HUTMR  
--------------------------------------------------------------------------------
1     10.1.1.252      00:0c:f7:ea:d2:00  Enable  Up    60     180    

2     20.1.1.252      00:0c:f7:ea:d2:01  Enable  Up    60     180    

VID   HDT REMAIN  HUT REMAIN  SMLT ID                               SLT ID                         
--------------------------------------------------------------------------------
1     60          180          1                                                                   
2     60          180          2                                      

 

Actually, the RSMLT of ERS8600 is done by responding peer IP/MAC address when the peer switch is down.  On the ARP table of ERS8600 B, the IP/MAC address of 10.1.1.252 and 20.1.1.252 are  learned via IST (MLT 3) while two ERS8600’s are joining a cluster.

ARP Table of ERS8600 B:

ERS-8606:5/show/ip/arp# info

================================================================================
                             IP Arp - GlobalRouter
================================================================================
IP_ADDRESS      MAC_ADDRESS        VLAN     PORT TYPE    TTL(10 Sec)
--------------------------------------------------------------------------------
10.1.1.253      00:0e:c0:32:e2:00  1       -     LOCAL   2160
10.255.255.255  ff:ff:ff:ff:ff:ff  1       -     LOCAL   2160
20.1.1.253      00:0e:c0:32:e2:01  2       -     LOCAL   2160
20.255.255.255  ff:ff:ff:ff:ff:ff  2       -     LOCAL   2160
10.1.1.240      00:0e:a6:b4:42:65  1     MLT 1   DYNAMIC 2160
10.1.1.251      00:19:e1:2d:d4:00  1     MLT 1   DYNAMIC 2135
20.1.1.251      00:11:58:96:43:c0  2     MLT 2   DYNAMIC 2105
10.1.1.200      00:0e:a6:aa:12:46  1     MLT 1   DYNAMIC 2085
30.1.1.253      00:0e:c0:32:e2:02  3       -     LOCAL   2160
30.255.255.255  ff:ff:ff:ff:ff:ff  3       -     LOCAL   2160
30.1.1.252      00:0c:f7:ea:d2:02  3     MLT 3   DYNAMIC 2160
10.1.1.252      00:0c:f7:ea:d2:00  1     MLT 3   DYNAMIC 2119
20.1.1.252      00:0c:f7:ea:d2:01  2     MLT 3   DYNAMIC 2119

13 out of 13 ARP entries displayed

After shutting down ERS8600 A, the original IP/MAC addresses of ERS8600 A are bound on ERS8600 B (Refer to the ARP table below). Therefore, a client only need to point either one as the default gateway and this reduces traffic interruption. 

ARP Table of ERS8600 B after ERS8600 A is down:  The IP/MAC address types of 10.1.1.252 and 20.1.1.252 are changed from dynamic to local.

ERS-8606:5# show ip arp info

================================================================================
                             IP Arp - GlobalRouter
================================================================================
IP_ADDRESS      MAC_ADDRESS        VLAN     PORT TYPE    TTL(10 Sec)
--------------------------------------------------------------------------------
10.1.1.253      00:0e:c0:32:e2:00  1       -     LOCAL   2160
10.255.255.255  ff:ff:ff:ff:ff:ff  1       -     LOCAL   2160
20.1.1.253      00:0e:c0:32:e2:01  2       -     LOCAL   2160
20.255.255.255  ff:ff:ff:ff:ff:ff  2       -     LOCAL   2160
10.1.1.240      00:0e:a6:b4:42:65  1     MLT 1   DYNAMIC 2159
10.1.1.251      00:19:e1:2d:d4:00  1     MLT 1   DYNAMIC 2159
20.1.1.251      00:11:58:96:43:c0  2     MLT 2   DYNAMIC 2159
10.1.1.252      00:0c:f7:ea:d2:00  1       -     LOCAL   2160
20.1.1.252      00:0c:f7:ea:d2:01  2       -     LOCAL   2160

9 out of 9 ARP entries displayed

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2 comments:

  1. Anonymous Says: November 28, 2009 at 8:05 AM  

    Great information, thanks.

  2. Anonymous Says: July 23, 2010 at 4:18 PM  

    Nice work.. great to see RSMLT config...

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