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Showing posts from March, 2016

nslookup Command

A Network Administrator command  which help diagnosis DNS related issue. However to understand this,  you should better to know how DNS works. How to troubleshoot DNS related issue. 1. NSLOOKUP example display "A Record" (IP Adress) of the domain C:\Users\jpudasaini>nslookup Server: Address: Non-authoritative answer: Name: Address: A Non-Authoritative Answer is a response from Cache. A DNS server is authoritative for zones actually holds it. The above output shows "A Records" (IP Adress) of the domain " ". Which is actually query to the public Google DNS. If you don't put DNS after the domain, it will used your default DNS, in my case I have used public DNS. 2. MX Record using -query=mx MX (Mail Exchange) record maps for the specific domain name to verify mail exchaing servers on that domain.

EoMPLS Configuration

EoMPLS is point to point L2 VPN services which is used to transport all Ethernet frame received on particular Ethernet or VLAN,  its also called Any Transport over MPLS(ATOM) means this technology can connect like Frame-Relay, PPP, Ethernet,ATM etc. IOS used c7200-adventerprisek9-mz.151-4.M Logical Topology   Make sure MPLS with IGP  is confugure as shown in a diagram. I'm not going to configure MPLS here. This tutorial only show how to configure xconnect tunnel peer with other side customer faces interface in our network diagram we interconnect PE1 fa1/0 with PE2 fa0/0 interfaces. Config of PE1 PE1#sh run Building configuration... Current configuration : 1337 bytes ! upgrade fpd auto version 15.1 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname PE1 ! ip cef interface Loopback0  ip address  ip ospf network point-to-point  ip ospf 1 area 0 ! interface FastEthernet0/0  ip ad

Configuring a Basic MPLS VPN

It's been a long time I'm away from blogging due to some R&D on the network with Juniper boxes. On this tutorial I'm going to configure very basic MPLS VPN configuration in GNS3. After that we go for EoMPLS configuration. This is the logical topology for this tutorial.   Here I only post the configuration file from PE other router configuration is almost same. Here is the points should be remember. 1. Make sure IGP with MPLS is configure on PE,P, it shouldn't be configure on customer facing interface. 2. Make sure all loopback interface is reachable.  3. Configure VRF with RD and RT, then applied it on right interface. 4. Configure MP-BGP on PE and peer it. 5. Make sure to redistribute the CE IGP protocol into the BGP and vice versa. Below command can be copy paste into your router. Before that make sure you had make change necessary things. Config from PE1 PE1#sh run Building configuration... Current configuration : 2126 bytes ! versi