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Re: [Wlug] SSH problems

by Gary Hanley

On Tue, 30 Sep 2008, Tal Cohen wrote: > Do you know the IP addresses of the users that ARE authorized to SSH into > the system? If so, add them to /etc/hosts.allow. > Tal Assuming you have TCP Wrappers built into your server of course. Maybe it's built in by default there days. I haven't built an SSH Server from source in a long time. But if you do have it installed I believe you can add the offending IP in /etc/hosts.deny which would be much easier. And even better-er, if the attacker is coming from one IP and you have a firewall it would be more efficient to stop them there before they reach the SSH service. -- Gary

Sept. 30, 2008

Re: [Wlug] SSH problems

by Chuck Anderson

On Tue, Sep 30, 2008 at 01:43:46PM -0400, Eric Martin wrote: > I have an outward facing ssh box at work that is currently being > attacked. somebody's going through a dictionary attack of usernames; > currently he or she is on abl. I can't block the IP Address because the > ip is different with each username. Does anybody have any good ideas on > how to stop this? I'm probably going to move the ssh port to some > random high number to get rid of this, but I don't know yet if anybody > else ssh's in besides me. > > Thanks in advance You could always just ignore it. Especially if you turn off password authentication and require users to use SSH RSA keys. Then no matter what dictionary attack it attempted, it will never work. I got sick of hearing my hard drive logging all the failed attempts and finally resorted to moving the SSH port.

Sept. 30, 2008

Re: [Wlug] SSH problems

by Tal Cohen

Do you know the IP addresses of the users that ARE authorized to SSH into the system? If so, add them to /etc/hosts.allow. Tal -----Original Message----- From: wlug-bounces(a)mail.wlug.org [mailto:wlug-bounces@mail.wlug.org] On Behalf Of Eric Martin Sent: Tuesday, September 30, 2008 1:44 PM To: Worcester Linux Users Group Subject: [Wlug] SSH problems I have an outward facing ssh box at work that is currently being attacked. somebody's going through a dictionary attack of usernames; currently he or she is on abl. I can't block the IP Address because the ip is different with each username. Does anybody have any good ideas on how to stop this? I'm probably going to move the ssh port to some random high number to get rid of this, but I don't know yet if anybody else ssh's in besides me. Thanks in advance -- Eric Martin Key fingerprint = D1C4 086E DBB5 C18E 6FDA B215 6A25 7174 A941 3B9F

Sept. 30, 2008

SSH problems

by Eric Martin

I have an outward facing ssh box at work that is currently being attacked. somebody's going through a dictionary attack of usernames; currently he or she is on abl. I can't block the IP Address because the ip is different with each username. Does anybody have any good ideas on how to stop this? I'm probably going to move the ssh port to some random high number to get rid of this, but I don't know yet if anybody else ssh's in besides me. Thanks in advance -- Eric Martin Key fingerprint = D1C4 086E DBB5 C18E 6FDA B215 6A25 7174 A941 3B9F

Sept. 30, 2008

Re: [Wlug] List broken?

by James Gray

Your message ended up in my gmail spam folder. Perhaps it ended up in yours as well? On Thu, Sep 18, 2008 at 3:58 PM, Tim Keller <turbofx(a)gmail.com> wrote: > I sent mail around 1am last night and it's yet to make it to the list...are > we having a problem? > > Thanks, > Tim. > > -- > I am weary of the allegiances of any politician who refers to their > constituents as "consumers". > > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug > >

Sept. 18, 2008

Re: [Wlug] List broken?

by Aaron Haviland

Tim Keller wrote, on Sep 18, 2008 at 15:58 EDT: > I sent mail around 1am last night and it's yet to make it to the list...are > we having a problem? Are your preferences set to receive a copy of mail sent to the list? (Edit your preferences here: http://mail.wlug.org/mailman/options/wlug) -- Aaron Haviland 34 Wayne Ave, Dudley, MA home: [508] 943 - 7974

Sept. 18, 2008

Re: [Wlug] List broken?

by Lee Keyser-Allen

Hrm, I saw it come through ... are your mail filters getting all aggressive against the Spam? On Thu, Sep 18, 2008 at 3:58 PM, Tim Keller <turbofx(a)gmail.com> wrote: > I sent mail around 1am last night and it's yet to make it to the list...are > we having a problem? > > Thanks, > Tim. > > -- > I am weary of the allegiances of any politician who refers to their > constituents as "consumers". > > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug > > -- Lee Keyser-Allen (lkeyser(a)alum.wpi.edu)

Sept. 18, 2008

List broken?

by Tim Keller

I sent mail around 1am last night and it's yet to make it to the list...are we having a problem? Thanks, Tim. -- I am weary of the allegiances of any politician who refers to their constituents as "consumers".

Sept. 18, 2008

Funky LVM hack we talked about...

by Tim Keller

Hey Gang, For those of you at the meeting who don't remember, Kevin had a 32GB flash disk that had a controller that had a built in understanding of FAT32. Thus formatting it as any other file system would work until you actually wrote to it then it would go insane. I postulated that one way to solve this would be to use LVM or MD, however when we tried this I hit a road block in that pvcreate won't let you pvcreate a regular old file, you need a device file, the same thing with MD. I finally managed to get it to work without having to hand add any devices into /dev... here's how... For my testing I created 4 100MB files using the command: dd if=/dev/zero of=part[1-4] bs=1024k count=100 This is what Kevin would need to do to on his flash drive... 1. Create 16, 2GB files on the flash drive named part[1-16] 2. Create loopback to file mappings using the command "losetup /dev/loop1 part1", repeat for all devices Also note, with this you could setup loopback encryption on these devices... If you suddenly find yourself without a loopback device issue the command in /dev "./MAKEDEV loop" However, I think udev will probably take care of it behind the scenes. 3. pvcreate /dev/loop1 /dev/loop2 /dev/loop3 /dev/loop4 ... 4. vgcreate vgHACK /dev/loop1 /dev/loop2 /dev/loop3 /dev/loop4 ... At this point if you issue a "vgdisplay" you should see how many (PE) physical extents you have. 5. lvcreate -n volume_name -l num_of_extends vgHACK If you use -L you can specify 300M, etc. Also you can specify how many stripes you want the data to be written in, which is handy if your 16 devices were on seperate disk controllers... Also you don't have to use all the extends in one logical volume, you could create lots of little volumes. 6. mkfs.ext3 /dev/vgHACK/volume_name 7. mount filesystem, sit back in bemusement that linux gives you the flexibility to do such things. Now... while were at it, if instead of LVM, if you wanted to use MD, this is what you'd do. If you have the lvm stuff from above, unmount the filesystem and issue a vgremove vgHACK it'll warn about active volumes, blah, blah... This command will take loop1,loop2,loop3,loop4 and put them into a 4 member RAID0 with no spare. mdadm -C /dev/md0 -l 0 -n 4 /dev/loop1 /dev/loop2 /dev/loop3 /dev/loop4 This command will create a raid5 out of the four devices without a spare. mdadm -C /dev/md0 -l 0 -n 4 /dev/loop1 /dev/loop2 /dev/loop3 /dev/loop4 It'll go off and build the array, now just format and mount and you're set to go. cat /proc/mdstat to see what it's upto. I was thinking of other insane things that Kevin can do with his 3 32GB flash disks. He could create 3 logical volumes each containing 16 members and then create an raid5 MD device using the logical volume members... He could create 3 16 member raid0's and then create a raid 5 out of them. He could install ZFS on top of fuse and then put all 48 devices into a zpool... I'll stop here, but I'm sure others have some even demented/funny ideas... Enjoy! Tim. -- I am weary of the allegiances of any politician who refers to their constituents as "consumers".

Sept. 18, 2008

Re: [Wlug] REMINDER: Upcoming Meeting on Wednesday

by E Johnson

Rich, > I'd be happy to see someone re-do the GIMP presentation. I really > wanted to see that, but I just couldn't make it. :-) I did the GIMP gig last time. I'll be there, & will bring the laptop again in case you want to see it. It wasn't that big of a presentation, but I could demo it again. I have questions about Hardy, but probably none that woiuld take very long to answer. Liz J

Sept. 16, 2008