ensnare's questions

I am currently using iptables for my home lab router and would like to add IPv6. I have 2 ISPs.

My first ISP assigns a /128 to the interface and the ability to request /56. ISP1 is connected to eno1.

My second ISP assigns a /128 to the interface and the ability to request /64. ISP2 is connected to eno2.

My LAN is enp2s0f0.

How can I get the clients on my LAN to use a ULA IP range that "maps" to the IPv6 ranges assigned dynamically to eno1 and eno2? I am thinking I can use some form of policy routing at the edge to route traffic through each ISP

I have a IPSec tunnel between two Pfsense machines. Both machines are connected to a 100mbps symmetrical connection. The latency between the two routers is ~70ms. I'm using AES-GCM-128 and SHA1, both machines support hardware acceleration of AES and CPU usage remains < 5%. But I'm having the strangest problem..

Bandwidth peaks around 6MB/s, then gradually decreases to 2MB/s, then gradually increases again to 6MB/s. It's a predictable sine wave. How can I get my bandwidth more consistent?

I tried enabling/disabling compression (currently disabled), playing with the MSS-clamp and MTU settings (1500/1460 respectively) and there doesn't seem to be a difference.

When I download a file directly through the public internet, I get 11MB/s which is closer to my 100mbps max.

What are some things I can try?

Does anyone have Squid3 working to successfully cache FTP requests coming in transparently? Should the proxy still listen on 3128, and I redirect incoming reuests on 21 to 3128?

I have a BIND nameserver on my network sitting on a machine with a lot of RAM. How can I increase performance? Any way to increase the TTL for which resolutions are stored in memory? Any way to "pre fetch" top domain names?

I have ~70ms latency over my VPN connection and need to set up a backup/replication system. SMB is the worst, with throughput ~200KB/s. SCP gives me ~400KB/s. HTTP ~700KB/s. The links are symmetric 50mbit connections.

Is there any kind of file transfer protocol designed for this kind of high latency connection?

Thanks.

I have directories sorted by date on different physical drives:

/mnt/drive1/2000
/mnt/drive1/2001
/mnt/drive2/2002
/mnt/drive3/2003
/mnt/drive4/2004
/mnt/drive4/2005
/mnt/drive5/2006

How can I get them to appear in a single folder, without using symbolic links?

/library/2000
/library/2001
/library/2002
/library/2003
/library/2004
/library/2005
/library/2006

Can I "mount" the folders to another folder? The reason I shy away from symlinks is because when I use applications like rsync and scp, I'd like to be able to copy to the symbolically linked directory without worrying about special flags to ensure the symlinks are followed.

Thanks.

My cisco edge router tags all incoming packets as IP precedence 0, 3, and 5 depending on their priority. How can I add a matching QoS configuration on the switch so that packets are prioritized appropriately?

I'm configuring two ethernet interfaces into an aggregation group to double bandwidth, and I was wondering if bond mode=0 works for all switches? What about dumb switches that don't support LACP? Will this methodology double bandwidth for a single host ("session")?

Does each packet get processed by a different core? Or is it a single-threaded process?

I have a small router without a keyboard and mouse, and I'd like to have it display network statistics using "jnettop" whenever the machine is booted up. How can I get the machine to display this information without requiring logging in and launching the application? The application jnettop requires root (I think) -- is this secure? If not, is there a better way to do this?

Thank you.

Is it possible to replace a 5/i controller without losing the data on the array? Can I import this as a foreign configuration? Any "gotchas" or tips to make this smoother?

I am seeing only 50MB/s reads:

ensnare@box:~$ sudo hdparm -tT /dev/sda
[sudo] password for ensnare:

/dev/sda:
 Timing cached reads:   4592 MB in  2.00 seconds = 2296.48 MB/sec
 Timing buffered disk reads:  192 MB in  3.90 seconds =  49.24 MB/sec

The array is already rebuilt and operational. Is this kind of slow performance normal? Anything I can do to make it faster? There weren't too many options in the controller configuration. Thanks.

How can I set up a site-wide rule to deliver all messages marked as Spam to the user's .Junk folder? And if the folder doesn't exist, create it. I know I can make a .forward file in the user's home directory, but I'm hoping there's a better way to do this. Thanks.

I just installed Exim 4.73 on Ubuntu using apt-get. I was able to easily integrate DKIM signing because of it's integration with Exim. I'm having some trouble with DomainKeys support. Most of the online documentation recommends compiling Exim with the DomainKeys library which I'd rather not do. Is there an easier way to have my Exim installation sign outgoing messages with a DomainKey signature? I noticed a package called dk-filter but couldn't find much documentation about it online. Thanks in advance.

What's the best linux distribution to put on a USB key to install the dell BIOS updates? I tried fedora but it was missing some dependencies and didn't work. Any instructions or step-by-step information is greatly appreciated. Thanks.

Does the dell Perc 6/i controller support 3TB drives?

I created a 7-drive RAID5 array with mdadm and put LVM2 on the array should I want to expand it in the future. I formatted as XFS. I basically followed this tutorial line for line:

Easy to expand Linux software RAID 5 with XFS. Best practices?

When I do

hdparm -tT /dev/md0 

I see read speeds of 400MB/s+

However via the network (gigabit crossover) I only get 55-60MB/s for both read and write. It's a pretty new machine (last 2 years)

What could be some sources of the bottleneck, and how can I fix them?

Thanks.

I have an XFS partition with a 64k blocksize. But I can only mount it in Ubuntu 10.10 when the blocksize is the default of 4k. How can I mount a partition with the larger blocksize?

This works:

sudo mkfs.xfs /dev/sdb1 -b size=4k -d agcount=32 -l size=128m -f
sudo mount /dev/sdb1 /mnt/media

This doesn't work:

sudo mkfs.xfs /dev/sdb1 -b size=64k -d agcount=32 -l size=128m -f
sudo mount /dev/sdb1 /mnt/media
mount: Function not implemented

I have a directory that contains symbolic links to other directories located on different media on my system:

/opt/lun1/2011
/opt/lun1/2010
/opt/lun2/2009
/opt/lun2/2008
/opt/lun3/2007

But the symbolic links show up as:

/files/2011
/files/2010
/files/2009
/files/2008
/files/2007

How can I perform an rsync that follows the symbolic links?

e.g.:

rsync -XXX /files/ user@server:/files/

How can I prioritize ssh traffic to ensure low-latency but throttle SCP file transfers? I'm looking for a solution that is not host specific so I don't have to add lists of IP addresses. Thanks!