Monday , December 11 2017

RIP loop protection

I am going to show you how RIP loop protection works. Let’s take the topology from the previous post to demonstrate the features.

RIP topology

There are 2 methods of loop protection: Split Horizon and Poison Reverse.

Split Horizon

It prohibits a router to advertise a route back to neighbors, through the interface that receives the routes. Split Horizon is enabled by default on Huawei routers:

[R1]display rip 1 interface Serial 0/0/0 verbose
Serial0/0/0(192.168.20.1)
State : UP MTU : 500
Metricin : 0
Metricout : 1
Input : Enabled Output : Enabled
Protocol : RIPv2 Multicast
Send version : RIPv2 Multicast Packets
Receive version : RIPv2 Multicast and Broadcast Packets
Poison-reverse : Disabled

Authentication type : None
Replay Protection : Disabled

Split Horizon is disabled

Read More »

basic concept of RIP

Routing Information Protocol RIP is an interior gateway protocol IGP, implemented based on a distance-vector algorithm.

RIPv1 characteristics
  1. A classful routing protocol
  2. Uses broadcast address to update routes
  3. Uses UDP port 520 to send and receive packets

Let’s look at the captured request and response packets of RIPv1:

RIPv1_request

RIPv1_response

Read More »

Inter-VLAN communication on USG firewall

It’s time to check a firewall available in eNSP simulator. Today a simple task, just configuring inter-VLAN communication on Huawei USG5500.

Let’s look at the following topology:

Configuration roadmap:

  1. Configure L2 communication on the switch.
  2. As the switch is L2, configure subinterfaces on the firewall and enable L3 communication between different VLANs.
  3. Set IP addresses and gateways for all PCs.
  4. Create 2 security zones and configure interzone packet-filterfing to control traffic between VLANs.
  5. Security requirements for the network:
  • PC1 in VLAN100 and PC2 in VLAN200 can communicate each other.
  • PC3 in VLAN300 can access PC1 and PC2. PC1 and PC2 cannot access PC3.

Read More »

Huawei eNSP – news

After long time a new version of Huawei eNSP has been released:

Huawei eNSP

New features:

  • Support CE6800 DC switch.
  • Support any wvrp device.
  • Export vrpcfg.cfg from usg5500.

Read More »

memory usage alarm threshold

 Huawei AR routers have easy and effective memory usage monitoring tool. When memory usage exceeds configured threshold, the system logs the event and generates an alarm. When memory usage falls within the alarm threshold, the system generates a clear alarm.

By default memory usage threshold is set to 90% when the memory capacity on the interface board is lower than or equal to 128MB, and 95% when the memory capacity is higher that 128MB. Memory usage threshold can be easly changed using command:

[labnario]set memory-usage threshold 75

Read More »