No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

FAQ - What Are Commonly Used Methods for Diagnosing NAT Service Faults on ME60 V6R5C00

Publication Date:  2013-09-22 Views:  10 Downloads:  0
Issue Description
What are commonly used methods for diagnosing NAT service faults on ME60 V6R5C00?
Handling Process
N/A
Root Cause
N/A
Solution

To identify whether a fault is a NAT fault, perform the following operations:

1. Check whether the number of sessions is normal. If the user proportion is with 150: 1 to 500:1, the number of engine sessions is normal.

<ME60>display nat statistics table slot 5
Slot: 5 Engine: 0
  Table statistic
   current ipv4 session speed(num/s)                                 1,120
   total current ipv4 sessions in Memory                           193,996
   current ipv6 session speed(num/s)                                     0
   total current ipv6 sessions in Memory                                 0
   servermap table number                                                        1
   frag table number                                                                     2
Slot: 5 Engine: 1
  Table statistic
   current ipv4 session speed(num/s)                                     0
   total current ipv4 sessions in Memory                                 4
   current ipv6 session speed(num/s)                                     0
   total current ipv6 sessions in Memory                                 0
   servermap table number                                                        2
   frag table number                                                                   193
Slot: 5 Engine: 2
  Table statistic
   current ipv4 session speed(num/s)                                     0
   total current ipv4 sessions in Memory                                 1
   current ipv6 session speed(num/s)                                     0
   total current ipv6 sessions in Memory                                 0
   servermap table number                                                        2
   frag table number                                                                   441

2. Check specific session table information with verbose. If packets are properly received and transmitted bidirectionally, NAT services are normal. Alternatively, check session tables by specific service (for example, display nat session table verbose slot 6 engine 3 destination global 121.15.109.210).

<ME60>display nat session table verbose slot 6
Slot: 6 Engine: 0
Current total sessions: 98164.
  udp: 10.10.23.177:24136[113.99.185.49:2118]-->66.130.61.28:50025  
  NAT Instance: nat_instance-2
  VPN:--->-
  Tag:0x80d,FixedTag:0x4004401, Status:no-hit, TTL:00:04:00 ,Left:00:03:04 , Master
  AppProID: 0x0, CPEIP:10.10.23.177, FwdType:FORWARD
  Nexthop:113.98.27.69
  -->packets:1, bytes:30, drop:0
  <--packets:0, bytes:0, drop:0

 udp: 10.10.22.244:20491[113.99.185.115:2086]-->113.111.88.239:11707  
  NAT Instance: nat_instance-2
  VPN:--->-
  Tag:0x80f,FixedTag:0x4004001, Status:hit, TTL:00:04:00 ,Left:00:00:57 , Master
  AppProID: 0x0, CPEIP:10.10.22.244, FwdType:FORWARD
  Nexthop:113.98.27.69
  -->packets:1749, bytes:131422, drop:0
  <--packets:1998, bytes:1335239, drop:0

3. Check user information by source IP address.

<ME60>display nat user-information cpe ipv4 10.10.3.101 slot 6
Slot: 6 Engine: 0
Total number:  1139.
  ---------------------------------------------------------------------------
  CPE IP                                :  10.10.3.101
  VPN Instance                          :  -
  Public IP                             :  113.99.185.218
  Start Port                            :  0
  Port Range                            :  0
  Total/TCP/UDP/ICMP Session Limit      :  0/0/0/0
  Total/TCP/UDP/ICMP Session Current    :  350/77/272/1
  Total/TCP/UDP/ICMP Port Limit         :  0/0/0/0
  Total/TCP/UDP/ICMP Port Current       :  0/0/0/0

4. Check traffic statistics, including the number of received, transmitted, and discarded packets, to determine whether engines receive and transmit packet properly.

display  nat statistics received slot 6
display  nat statistics transmitted slot 6
display  nat statistics discard slot 6

If a large amount of statistic data exists, run the reset nat statistics all command after saving historical statistic data.
Suggestions

To troubleshoot a NAT fault, perform the following operations:

1. Focus on route changes on uplink devices to check whether routes to downlink devices are available if only users transmit packets to the network but the network does not transmit packets to the user.

2. Rectify faults according to the packet discarding causes displayed in the statistic data.

For example, for fib miss, check the route changes.

setup session fail

3. Reset the NAT board in an emergency. If a backup board is available, services are not affected. If no backup board is available, services can recover after the reset board starts working.

END