3,901 reputation
916
bio website
location London, United Kingdom
age 43
visits member for 5 years, 2 months
seen Aug 5 at 11:13
Quite boring, really. Have faffed about with computers since the mid-80s, have worked as a network engineer, unix sysadmin and (occasionally) developer.

Nov
8
comment How can I troubleshoot excessive latency between client and server?
The interesting bit isn't if the client end has DNS issues, it's if the server end has it.
Oct
24
comment How does Ethernet know how long a frame is?
The end of frame in "classic Ethernet" is signalled by an illegal encoding.
Oct
14
comment Splunk File & Directory Data Inputs
It looks as if you've configured your linux hosts to forward all syslog messages to 192.168.254.100, I guess this is your Splunk host? If so, try restarting syslog (or forcing it to re-read the config file).
Oct
14
comment How to copy a large number of files quickly between two servers
Also, if you have plenty of CPU available (on both ends), but (at least) a slow link between the hosts, it may be worth enabling compression (gzip or bzip) in the tar command.
Oct
14
comment Is Internet routing (BGP) fully automated?
The one thing that RIPE does that (should, but doesn't necessarily) influence(s) routing is publishing route-set information. That is, what route-sets a given AS imports, exports and originates. This can then be used to automatically build filters to protect against rogue announcements.
Oct
14
comment What security risks are there with employees using Dropbox?
It also poses a problem for any EU business, as there's obvious risks for personal data to end up in uncontrolled environments. The same goes for any US business who wants to keep a Safe Harbor certification (so they can process EU personal data).
Oct
12
comment Need a recipe following a hack disaster
I'd change that to "restore from known-unhacked backups", restoring a system that has been hacked, from a backup done after the hack, is about as useful as not nuking and restoring in the first place.
Oct
12
comment Tough routing problem with Linux, Quagga and OpenVPN
@Antoine Benkemoun: The default route is installed on each "VPN client", pointing across the VPN tunnel, towards the concentrator. You'd obviously need a route for the VPN concentrator, routed back across whatever the "phsyical default gateway" would be for the VPN client. If you install a static route for 192.168.1.0/24, with a next-hop of 10.8.0.4, does it work then?
Oct
11
comment In Linux, are ALL user permissions attached to an object?
Well, everything is a file, a semaphore, a message queue, a non-FS-attached shared memory segment or a socket (and sockets are pretty darned file-like, except they normally don't live in a file-like namespace).
Oct
8
comment Make bridge table with UDP packet
@Amirreza: Normally, the MAC address table is pretty static, once populated and doesn't time out. ARP entries do time out (varying between 5 minutes and a couple of hours, depending on the kit). So having ARP tables populated on the hosts, but no forwarding table on the switch would be pretty unlikely (although possible).
Oct
6
comment Management Network Best Practices
Does your RADIUS server check the originating IP of the requested management connection? The typical use for bastion hosts is to have a small set of ACLs (on the devices or on a firewall between "normal" and "management" network) to limit woh can manage. Couple that with a single (or a limited) amount of hosts where you manage accounts and you've decreased your management burden.
Oct
4
comment Make bridge table with UDP packet
In the typical case, the routers in-between your hosts will NOT accept any routing update you are wanting to make to them. Or, at least, they SHOULD not accept routing updates unless they're signed with the right key.
Oct
3
comment Does Default Gateway IP = Router IP?
Well, I suspect I can make that happen on my 50 quid Zyxel, but I have absolutely no need for it.
Oct
2
comment Slow Performance with MPLS
Sounds like a physical issue with the port, but I must say I have a hard time articulating a reasoning behind that.
Oct
2
comment Does Default Gateway IP = Router IP?
Unless you store your router's management address yourself, it's simply not there to retrieve. But, as I said, the only time it's likely to differ is when you have a network with tens, hundreds or maybe thousands of routers.
Oct
1
comment Cisco 3550 internal queue statistics under IOS 12.1?
Wish it had been that easy. In the past, we've had QoS problems on this (yeah, yeah, I know, QoS and switch-based networks ain't the best in the world, but it's a pretty large network and a bit too late in the day to rip it apart and start from scratch).
Sep
30
comment What is the difference between BGP and OSPF?
OSPF or IS-IS to distribute your loopback addresses, BGP to carry all other routing info. Makes the bulk nice and simple. Saying that, OSPF is surprisingly simple, if your network has a topology suited for OSPF. Imposing OSPF on a network can be a nightmare.
Sep
29
comment How do I edit the crontab of another user on my linux server?
The [ -u user ] means that you can optionally say -u user. I would've expected to see user either in italics (when typeset) or as <user> to indicate that it's not the literal string "user" you need to give,
Sep
28
comment VLAN vs traditional switch technology
There's also some downsides. VLANs (especially with trunks between switches, quite common as it were) have some interesting gotchas from a security POV. If you're relying on VLAns to segregate "hostile" networks, bear in mind that even an access port can act as a trunk, if you send .1q packets at it (in-so-far as it will then send packets on in the "wrong" VLAN).
Sep
26
comment How to do a post-mortem of a server hack
I'd say that you are probably better off doing step #2 every time, since you're not entirely sure what you'll find during your investigation. Having binary images also means that you can have different people looking at different things, using a copy each.