Slow speeds across an office link

Posted on 2014-12-10
Last Modified: 2016-11-23
We have recently been trying to implement a Server 2012 instance of DFS across 2 of our main sites.  The servers are Dell R720xd with Intel NICs installed with all the latest firmware drivers and updates installed.  When the machines were on the same site, transfer speeds where 100-105MB/s transferring between them, however as soon as one was transferred to another site, these speeds have become 1-2MB/s.  The link between the offices is a dedicated 100MB link with a single hop between our 2 main sites; ping response between the 2 sites is between 26ms (empty office) to 35ms (both offices at peak times).  Our other site in London has a ping response of 20-21ms to our Liverpool site and doesn't experience these issues at all; achieving around 9.5MB/s transfer during peak times (it will hit almost 11MB/s when offices are quiet).

We have had our ISP investigate the link between our Manchester and Liverpool sites and can't find anything wrong at all; when we try and transfer a file from our old Netapp appliance (FAS2020) to the other site we achieve a much quicker 6-8MB/s (although it starts at around 2-3MB and climbs slowly).

We tried the various tweaks and policy changes on 2012 (disabling autotuning, rss, tcp chimney offload, bandwidth throttling, SMB signing etc) but to no avail.  So we downgraded one of the servers to 2008 R2 and performed the same steps - unfortunately we still experience the same problems!

I am rapidly running out of ideas here - I thought the bandwidth throttling reg fix would sort our issues, but it appears not; although I had my suspicions that a 30ms ping time would not be classified as high latency enough to throttle back bandwidth.

Can anyone help??
Question by:Amaze_IT
LVL 57
ID: 40490941
One thing that comes to mind is MTU size; you say this is point to point, but are your running a VPN to get that or is it truly a dedicated point to point (which is getting to be rare)?   If so, you might be fragmenting a lot of packets.

LVL 16

Expert Comment

by:Dirk Mare
ID: 40491833
Are you getting those speeds on all portocols?

Can you run speedtest using TCP and UDP?

+ 1 for MTU settings


Author Comment

ID: 40544778
We are not running a VPN between the sites, we are running straight links with acls through our ISP to avoid as much latency as possible (NOT public links!)  i've been through the configuration with our ISP and we have attempted to modify the MTU size on both our servers and through their routers, but the problem persists regardless.

The strange thing is, when we reboot a router (power off) the speed jumps up and then will gradually die off again over a period of 12 hours of so?  Seems to be regardless of protocols
Is Your AD Toolbox Looking More Like a Toybox?

Managing Active Directory can get complicated.  Often, the native tools for managing AD are just not up to the task.  The largest Active Directory installations in the world have relied on one tool to manage their day-to-day administration tasks: Hyena. Start your trial today.

LVL 14

Expert Comment

ID: 40548652
Just a suspicion: maybe you have some kind of name resolution problem ? If the machines run into a timeout every time they try to resolve a name that would slow many things down ... that might be i.e. if you have set upü name resolution by DNS and the machines try to resolve with WINS first ... check the preceedence of the name services or put the critical ones into the HOSTS file, which is evaluated first.

There are possibly more trapdoors like that ...

Author Comment

ID: 40563923
I did check with regards to name resolution as a saw a few people mention this as a possible issue; i even went so far as to reinstall and configure WINS across the sites to ensure there was no problem there; then i did the registry key to force the system to use DNS only - all to no avail.  The have AD integrated DNS, each DC is also a DNS server, primary server is the local site, then secondary is always the central site main DNS server.  All looks to be good!  Althought to be honest I did not test the use of HOSTS file entries for the DNS/AD servers as well.  worth a shot i guess..
LVL 14

Expert Comment

ID: 40563931
Maybe a look at the HOSTS file would help .. if there are wrong entries, name resoution would be a hassle.

The HOSTS file is evaluated first ... sometimes anti-malware-tools put many entries in to prevent malware from calling home. If i contains hundreds of entries, checking it could have an impact on name resolution performance.
LVL 14

Accepted Solution

frankhelk earned 500 total points
ID: 40563932
Maybe a look at the HOSTS file would help .. if there are wrong entries, name resoution would be a hassle.

The HOSTS file is evaluated first ... sometimes anti-malware-tools put many entries in to prevent malware from calling home. If i contains hundreds of entries, checking it could have an impact on name resolution performance.

Featured Post

Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Import groups from "Member Of" of user to a notepad. 4 49
non-domain members are not prompted for credentials 18 43
SQL Replication question 9 43
SQL Cluster Upgrade 1 22
Windows 7 does not have the best desktop search built in. This is something Windows 7 users have struggled with. You type something in, and your search results don’t always match what you are looking for, or it doesn’t actually work at all. There ar…
New Windows 7 Installations take days for Windows-Updates to show up and install. This can easily be fixed. I have finally decided to write an article because this seems to get asked several times a day lately. This Article and the Links apply to…
This tutorial will walk an individual through the process of transferring the five major, necessary Active Directory Roles, commonly referred to as the FSMO roles to another domain controller. Log onto the new domain controller with a user account t…
This tutorial will walk an individual through setting the global and backup job media overwrite and protection periods in Backup Exec 2012. Log onto the Backup Exec Central Administration Server. Examine the services. If all or most of them are stop…

832 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question