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Forum Replies

  1. Rene,
    Hi. Great explanations. Couple quick clarifications.

    1. You mention ‘The MSS value isn’t synchronized between hosts, it can be different for each direction’ - I thought this gets negotiated as a part of the 3 way handshake? Are you saying in your example above if say set “ip tcp adjust-mss 1360” on the f0/1 of R2 and then set “ip tcp adjust-mss 1460” on the f0/1 of R1 then it wouldnt negotatiate down to the lowest common MSS and hence break?

    2. Assuming I am using GRE over IPSEC with transport mode I looked at a recent customer network in which the tunnel i

    ... Continue reading in our forum

  2. Hi Rene,

    As you mention the interface MTU for both end doesn’t need to be same.

    If let say R1 with interface MTU 9000 and R2 with interface MTU 1500. It will not cause any issue?

    Because the R1 sending 6 times more packet in one frame, R2 will able to receive it without any problem?

    Davis

  3. Hello Sameer.

    The quick answer is yes. Fragmentation will occur during encapsulation. If a PC is preparing an email to send, it will take the transport segment and encapsulate it into an IP packet. An IP packet can theoretically be up to 65535 bytes long. So during encapsulation from the Network to the Data Link layer on the PC, if an IP packet is larger than the allowable 1500 bytes

    ... Continue reading in our forum

  4. Got a few questions-

    1. You mention that it is no problem when the frame reaches 1514 bytes, but realistically how high can this go before it starts causing an issue on Ethernet?

    2. Why did it cause a problem communicating with the web server when you reduced the MTU to 1400? Should it not have just fragmented it? Is the DF bit used in HTTP? I mean it would slow things down a bit to fragment, but not stop them working altogether?

    3. What happens if one side has an MTU of 1400, and the other 1500? Does the side set to 1400 have an issue receiving packets over this

    ... Continue reading in our forum

  5. ... Continue reading in our forum

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