Tag Archives: huawei router

routing policy configuration

Some time ago I wrote about local PBR and interface PBR.

It’s time to talk about routing policy, that is a different mechanism. Routing policy is applied to routing information and it is combined with routing protocols to form policies. PBR mechanism is applied to data flows and and packets are forwarded according to the configured policy.

Routing policy is a tool which can be used to filter routes and set route attributes, when importing routing information into OSPF, RIP, ISIS or BGP protocols. BGP can use routing policy to filter advertising routes as well. Routing policy defines which of the routes from the specific routing protocol are allowed to be imported into the target routing protocol. It can be also used to match routes or certain route attributes and to change these attributes when the matching rules are met.

Routing policy command syntax:

route-policy route-policy-name { permit | deny } node node

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IP FRR on Huawei routers

What do we have in traditional IP networks?

Let’s assume that there is a fault at the physical or data link layers. Router sees that a physical interface becomes DOWN. After the router detects this fault, it informs upper layer routing system to update routing information. The convergence time is several seconds, what is critical for sensitive services.

That’s why IP FRR has been developed. After we configure IP FRR, a router doesn’t wait for network convergence but a backup link is immediately used to forward packets.

We have 2 scenarios of using IP FRR:

  1. To protect routers in public networks.
  2. To protect CE routers in private networks.

Let’s focus on the first one.

IP FRR topology Continue reading

configuring SNMPv3 on Huawei devices

SNMPv1 and SNMPv2c protocols security model uses the community-based pseudo-authentication. That means that a password (called a community string) is sent in a clear text between a network management station and managed devices. Both SNMPv1 and v2c are subject to packet sniffing because they do not implement encryption. Security has been the biggest weakness of the SNMP since the beginning. More about SNMPv2c concepts, operation and configuration you can find at “SNMPv2c configuration on Huawei devices“.

What if we want SNMP to be used over a public network?

SNMPv3 can be implemented. It provides important security features, which are not available in both SNMPv1 and v2c:

  • Confidentiality – encryption of packets to prevent snooping by an unauthorized source
  • Integrity – to ensure that a packet has not been tampered while in transit using optional packet reply protection
  • Authentication – to verify that a packet comes from a valid source.

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l2tp LAC-auto-initiated tunnel mode

Layer 2 tunneling protocol (L2TP) connection can be established in the following tree modes:

  • NAS-initializated
  • Client-initializated
  • LAC-auto-initializated.

This is not my job to tell you about the theory. You can find plenty of information about L2TP on the internet. Let’s focus today on the third mode.

In most cases, an L2TP user directly dials up to a LAC, and only PPP connection is established between the user and LAC. Unlike NAS and Client-initializated modes, in LAC-auto-initializated mode users can connect to the LAC by sending IP packets. At the same time LAC needs to have a PPP user created and a tunnel with the LNS established. The two ends of an L2TP tunnel reside on LAC and LNS respectively. As you can see from the topology below, in LAC-auto-initiated mode, LAN can be directly connected to LAC.

L2TP topology Continue reading

from Huawei CLI – “user-interface current”

Sometimes we want to change any parameter of our current user interface quickly, let’s say terminal length or idle timeout, but we don’t know which user interface we are currently using. To check that we use “display user-interface” command. Then we try to find the “+” mark in the command output, which means that this is our current user interface. After that we have to go back to our user interface configuration and change its parameters. Why not to do that in a quicker manner?

[labnario]display user-interface
  Idx  Type     Tx/Rx      Modem Privi ActualPrivi Auth  Int
  0    CON 0    9600       -     15    -           P     -
  33   AUX 0    9600       -     0     -           P     -
+ 34   VTY 0               -     0     3           A     -
  35   VTY 1               -     0     -           A     -
  36   VTY 2               -     0     -           A     -
  37   VTY 3               -     0     -           A     -
  38   VTY 4               -     0     -           A     -
  50   VTY 16              -     15    -           A     -
  51   VTY 17              -     15    -           A     -
  52   VTY 18              -     15    -           A     -
  53   VTY 19              -     15    -           A     -
  54   VTY 20              -     15    -           A     -
UI(s) not in async mode -or- with no hardware support:
  +    : Current UI is active.
  F    : Current UI is active and work in async mode.
  Idx  : Absolute index of UIs.
  Type : Type and relative index of UIs.
  Privi: The privilege of UIs.
  ActualPrivi: The actual privilege of user-interface.
  Auth : The authentication mode of UIs.
      A: Authenticate use AAA.
      N: Current UI need not authentication.
      P: Authenticate use current UI's password.
  Int  : The physical location of UIs.

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