Re: Kerberos UDP vs TCP

Hi Paolo

The main reason for using UDP by default is that it's lightweight compared
to TCP. Also the fact most LAN networks are reliable and UDP traffic will
normally make it through without any problems.

UDP starts having problem if the network is not reliable, i.e. busy network,
slow links, or has packet loss. The advantage of using TCP is that it uses
acknowledged delivery. The downside is the protocol overhead to support
acknowledgement mechanism, this increase the amount of traffic that is
transmitted.

One of the problem I've have seen in the past with WAN connection is VPN or
encryption over head, this reduces the overall packet size. The UDP
transmissions don't take into account reduced window size and as a result
packets can be lost. When using TCP both ends agree the max window size,
preventing packet loss.

Overall the impact on the network is an increase in traffic, however, you do
get guaranteed delivery!

Hope his helps
Gary.



"paolo valsecchi" <paolovalsecchi@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in
message news:AB16D9B0-A2DA-48C0-8015-ADF6022D6FD2@xxxxxxxxxxxxxxxx
Hi everybody
I'm facing some problems with Kerberos authentication using UDP protocol.
As suggested by Microsoft using TCP protocol the problem has been solved
instead.

Questions:
Why Microsoft uses UDP by default if there are authentication problems?
What would be the global impact on the network (WAN) using Kerberos
authentication through TCP? Would it be a suitable solution?

Any help really appreciated.



.

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