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Quidway NetEngine5000E Attaches Quidway MA5200G and then Network Segment cannot be Distributed

Publication Date:  2012-07-27 Views:  51 Downloads:  0
Issue Description
GSR              GSR
 |                |
 |                |        
Jiangnan NE5000E----Jiangbei NE5000E
                  |
                  |
               MA5200G
                  |
                  |
              Switch of Convergence Layer
Main configuration:
Jiangbei NE5000E related configuration:
   network 218.14.116.0 255.255.252.0
   ip route-static 218.14.116.0 255.255.252.0 NULL0 preference 180
   ip route-static 218.14.117.202 255.255.255.255 125.93.0.101     //It is static route to MA5200G loopback address.
Jiangnan NE5000E configuration:
    
    network 218.14.116.0 255.255.252.0   
    ip route-static 218.14.116.0 255.255.252.0 NULL0 preference 180
MA5200G points to Jiangbei NE5000E through static route.
On MA5200G loopback is source address:
ping -a 218.14.117.202 202.96.128.86 (Guangdong DNS) is unreachable.
   ping -a 218.14.117.202 202.103.96.112( Hunan DNS) is reachable.
   ping -a 218.14.117.202 61.140.4.144(Guangdong radius server) is unreachable.
   ping -a 218.14.117.202 61.140.4.111(Guangdong radius server) is reachable.
   ping -a 218.14.117.202 202.97.28.83(Guangdong  NR1) is reachable.
The result on Jiangbei NE5000E:
   dis ip rou 218.14.117.202
   Routing Table : Public
   Summary Count : 1
   Destination/Mask    Proto  Pre  Cost       NextHop         Interface
   218.14.117.202/32  Static 60   0          125.93.0.101    GigabitEthernet3/0/3.190                                                                                
   dis ip rou 218.14.117.202 verbose
Routing Table : Public
Summary Count : 1
Destination: 218.14.117.202/32
     Protocol: Static          Process ID: 0
   Preference: 60                    Cost: 0
      NextHop: 125.93.0.101     Interface: GigabitEthernet3/0/3.190
  RelyNextHop: 0.0.0.0          Neighbour: 0.0.0.0
    Tunnel ID: 0x0                  Label: NULL
        State: Active Adv GotQ        Age: 1d03h58m52s
          Tag: 0                                                                
Alarm Information
Null
Handling Process
Check Jiangnan NE5000E configuration:
    
    network 218.14.116.0 255.255.252.0   
    ip route-static 218.14.116.0 255.255.252.0 NULL0 preference 180   
    
Jiangbei NE5000E is attached MA5200G and the loopback Jiangbei NE5000E configures to MA5200G is static route and Jiangnan has no configuration. 
 
The result on Jiangnan NE5000E:
   dis ip rou 218.14.117.202
   Routing Table : Public
   Summary Count : 1
   Destination/Mask    Proto  Pre  Cost       NextHop         Interface
   218.14.116.0/22  Static 180  0             0.0.0.0          NULL0
 
dis ip rou 218.14.117.202 verbose
Routing Table : Public
Summary Count : 2
Destination: 218.14.116.0/22
     Protocol: Static          Process ID: 0
   Preference: 180                   Cost: 0
      NextHop: 0.0.0.0          Interface: NULL0
  RelyNextHop: 0.0.0.0          Neighbour: 0.0.0.0
    Tunnel ID: 0x0                  Label: NULL
        State: Active Adv             Age: 58d18h20m29s
          Tag: 0
Destination: 218.14.116.0/22
     Protocol: BGP             Process ID: 0
   Preference: 200                   Cost: 0
      NextHop: 218.14.117.214   Interface: Pos1/0/2
  RelyNextHop: 218.14.111.26    Neighbour: 218.14.117.214
    Tunnel ID: 0x0                  Label: NULL
        State: Inactive Adv GotQ      Age: 52d16h09m10s
          Tag: 0 
 
Solution:
On NE5000E import static route to OSPF. Jiangnan NE5000E can learn static route to MA5200G and has to filter blackhole route.
Root Cause
The forwarding path from public network to MA5200G loopback can enter into MAN through Jiangnan NE5000E or Jiangbei NE5000E.
If the destination address from Jiangbei NE500OE is 218.14.117.202, Jiangbei NE5000E checks routing table and there is a route:
   ip route-static 218.14.117.202 255.255.255.255 125.93.0.101     //It is static route to loopback address of MA5200G priority 60     
It will match the route to MA5200G and it is reachable.
If the destination address from Jiangnan NE5000E is 218.14.117.202, Jiangnan NE5000E checks routing table and there are two routes:
1. blackhole route: OSPF routing table has no accurate route 218.14.117.202 ( MAN interior IGP ospf does not distribute and learn it.) And configured blackhole route:
    Destination: 218.14.116.0/22
     Protocol: Static          Process ID: 0
   Preference: 180                   Cost: 0
      NextHop: 0.0.0.0          Interface: NULL0
  RelyNextHop: 0.0.0.0          Neighbour: 0.0.0.0
    Tunnel ID: 0x0                  Label: NULL
        State: Active Adv             Age: 58d18h20m29s
          Tag: 0
2. IBGP route: Jiangbei network distributes it and Jiangnan learns it:
     
  Destination: 218.14.116.0/22
   Protocol: BGP             Process ID: 0
   Preference: 200                   Cost: 0
      NextHop: 218.14.117.214   Interface: Pos1/0/2
  RelyNextHop: 218.14.111.26    Neighbour: 218.14.117.214
    Tunnel ID: 0x0                  Label: NULL
        State: Inactive Adv GotQ      Age: 52d16h09m10s
          Tag: 0   
BGP configuration: IBGP preference is 200 and is sub-preference. The destination address 218.14.117.202 to Jiangnan NE5000E is discarded.
Suggestions
The configuration of BGP should be considered globally.

END