BGP Weight

BGP Weight is the first BGP attribute if we dive deep into BGP’s algorithm of best path selection followed by Local_Preference & aggregate (detailed in my first post in BGP section). Weight is vendor specific (Cisco proprietary) so it is found only on Cisco routers. Weight is always local on a router and it is […]

Wireshark Operators

Wireshark is the most useful & popular tool for packet Level deep Network Analysis & Troubleshooting. Most importantly, it is open source. It is like a measuring meter or device to find and examine what is going on inside a network cable or port just like a multimeter is used by an electrician to examine […]

MP-BGP and Address Families

BGP originally only supports normal IPv4 unicast prefixes. With the passage of time & advancement in Network Technology, the need for support of more prefix types arose. There were two solutions to this problem: First, to invent a whole new protocol or a new version of BGP, Second, to add the extra functionality in the […]


TLV (Type-Length-Value or Tag-Length-Value) is an encoding scheme used for optional information element in a certain protocol. The type and length are fixed in size (typically 1-4 bytes), and the value field is of variable size. Type: It is simply the data being processed, a binary code, often simply alphanumeric, which indicates the kind of field that this […]

IS-IS Levels & Relationships

IS-IS creates flooding boundaries logical by breaking the network into routing domain levels i.e. A level2 routing domain and multiple level1 routing domains. The single Level 2 routing domain could be analogous to OSPF Area0 and multiple Level 1 routing domains are analogous to other OSPF Areas. Basically, IS-IS has two layer hierarchy: Level-2 (the backbone) Level-1 […]