Juniper JN0-351 Dumps Questions Answers

The maximum allowable MTU size for a default GRE tunnel without IPv4 traffic fragmentation is 1476 bytes 1 .  This is because GRE packets are formed by the addition of the original packets and the required GRE headers 1 .  These headers are 24-bytes in length and since these headers are added to the original frame, depending on the original size of the packet we may run into IP MTU problems 1 .  The most common IP MTU is 1500-bytes in length (Ethernet) 1 .  When the tunnel is created, it deducts the 24-bytes it needs to encapsulate the passenger protocols and that is the IP MTU it will use 1 .  For example, if we are forming a tunnel over FastEthernet (IP MTU 1500) the IOS calculates the IP MTU on the tunnel as: 1500-bytes from Ethernet - 24-bytes for the GRE encapsulation = 1476-Bytes 1 .

The bridging table is a data structure that stores the MAC addresses and the associated interface details and MAC learned time for each MAC address. The bridging table is used by the switch to forward frames based on the destination MAC address. The ether type details and the preamble of Ethernet packet are not stored in the bridging table, as they are not relevant for the switching process. References:

Enterprise Routing and Switching, Specialist (JNCIS-ENT) - Juniper Networks

Enterprise Routing and Switching, Specialist (JNCIS-ENT) - Juniper Networks

[Junos OS Layer 2 Configuration Guide - TechLibrary - Juniper Networks]

[Junos OS Layer 2 Configuration Guide - TechLibrary - Juniper Networks]