When Two Outlets Are Used, One Outbound Address Cannot Be Reached Using Telnet

Publication Date:  2013-12-31 Views:  227 Downloads:  0
Issue Description

A USG2100 has a PPPoE link for office and Internet access and a leased line for server access. According to the feedback from the customer, the address 1.1.1.1 can be reached from the public network using Telnet, but the address 2.2.2.2 cannot be reached using Telnet.
Alarm Information
None
Handling Process
1. Check the routing table.
dis ip routing-table
Destination/Mask    Proto  Pre  Cost     Flags NextHop         Interface
       0.0.0.0/0    Static 60    0          D  1.1.1.2   Dialer1
2. Use Telnet to reach 2.2.2.2.
telnet  VPN:public --> public
  Zone: dmz--> local  TTL: 00:00:05  Left: 00:00:00
  Interface: InLoopBack0  NextHop: 127.0.0.1  MAC: 00-00-00-00-00-00
  <--packets:0 bytes:0   -->packets:1 bytes:48
  3.3.3.3:34553-->2.2.2.2:23
3. Configure local PBR to transmit data packets whose source address is 2.2.2.2 through the next hop along the leased line.
acl 3005
rule 5 permit ip source 2.2.2.2  0

policy-based-route aaa permit node 1
  if-match acl 3005
  apply ip-address next-hop  2.2.2.1
4. Use Telnet to reach 2.2.2.2.
telnet  VPN:public --> public
  Zone: dmz--> local  TTL: 00:10:00  Left: 00:09:57
  Interface: InLoopBack0  NextHop: 127.0.0.1  MAC: 00-00-00-00-00-00
  <--packets:15 bytes:1181   -->packets:13 bytes:581
  3.3.3.3:34400-->2.2.2.2:23
The lease line address can be reached from the public network using Telnet.
5. Check PBR.
[USG2100]display  ip policy-based-route   statistics  local
16:20:06  2013/02/06
Local policy based routing information:
policy-based-route: aaa
   permit node 1
     apply ip-address next-hop  2.2.2.1
       Denied: 0,
       Forwarded: 48
Total denied: 0, forwarded: 48
PBR forwarding is successful.
Root Cause
The response packets to the USG2100 may be transmitted along the PPPoE link.
Suggestions
When multiple outlets are available, inconsistent paths for incoming and outgoing traffic lead to a Telnet failure.

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