[c-nsp] Slow 2008R2

[Phil Mayers]

On 11/17/2012 01:20 AM, Don Vliet wrote:
> First post to list...
>
>
>
> Hello, I am looking for information on possible fixes, changes to
> configuration, etc for my Cisco devices (or Windows) that may be
> applicable for tuning network performance when introducing Windows
> 2008R2.  I have found many things through Google but have not solved my
> issue yet.  The network equipment involved is a Cisco router 1811 and a
> few switches (Catalyst 3550-12T / 12G / 48 / 24).
>
>
>
> Originally my network was only W2003R2 Ent or Std and my speed was very
> good.  I upgraded most of my servers including the file server to
> W2008R2 Ent and now I sometimes get huge lag times when connecting to or
> copying from the file servers...

Someone else has already posted some links for actual throughput issues, 
but one other thing you might want to check - the presence of IPv6, and 
whether there is some brokenness or tunnelling going on.

Note: just because *you* haven't configured IPv6 doesn't mean it's not 
there; windows does 6to4 tunnelling by default, and will insert itself 
into dynamic DNS with those tunnelled IPs.

2008r2 comes with IPv6 enabled by default, which stood out at me when 
you described your symptoms, particularly slow connections.

Check for:

  1. IPv6 addresses in "ipconfig /all"
  2. If present, that those IPv6 addresses have working connectivity
  3. AAAA records in your DNS (likely, if you are using MS DNS with 
dynamic updates)
  4. If present, that the addresses in those AAAAs are reachable
  5. My advice would be to disable ISATAP, 6to4 and Teredo by group 
policy and either deploy native IPv6, or ensure it's properly blocked 
including from leaked RAs (e.g. from hosts with Internet Connection Sharing)

HTH

Cheers,
Phil