Archive for September 12th, 2011

Over the roof and through the walls to your PC we go….

Well we have been doing a lot of work in Miami these past few weeks for a customer who runs quite a few childern’s schools. We are actively getting two of them up to par as far as their requested needs are concerned for their network. With cabling and L2 planning we have our work cut out for us. The hardest thing about retrofitting is walls and budget.

For this new project we have to setup wifi across two buildings. While avoiding digging, concrete cutting, and keeping patching to a minimum. This will allow the customer to stay on the low end of pricing and give them what they need. Its really small in comparison to some work I have seen but the walls are so thick it presents a new challenge. A gain antenna will most definitely be needed to get enough signal through the wall. I don’t want a cable strung across the roof of the buildings either. So here is the plan. We get a simple router with a outside grade antenna that will amplify the signal and give us the power to push data through the walls. I have already used an old Linksys B router and my laptop to test. I set the router up in the main building on the right and pinged from the farthest class room in the left building with decent delay in pings but with a horrible signal that would surely be affected by a gust of wind. Yet enough to at least view a simple web page is my thought. Now to make it even better I am thinking (as I write this) that we can use an antenna on the 5GHz spectrum to avoid microwave signals and some power line interference if any in the area. Plus there is an airport near by which may interfere. My hope is that it also survive possible rain storms….hoping, though I have expressed this to the customer as a cause of disruption and they understand.

With my research thus far i fing that 5GHz routers are priced high and the antennas out there are mostly for the 2,4GHz band. This is fine though cause I can use the old faithful WRTG54L routers that everyone knows and loves.  Planning out this branch though does make me think about getting all sites connected. So far i ahve been to three of their facilities and I see they have 6. Possible Site to Site VPN tunnels that leverage their current DSL or possible PTP connections to a central hub. The latter is wishful thinking and not really needed. Though it doesn’t need so much processing power to accomplish. The cost is still high it just cooler for centralized services like backups.

Im thinking that with this setup another antennae could be put on the opposite side of the main building, if needed, to give internet access to the play ground which stretches to the length of a football field. Again, if needed.



Rookie Mistake!

OK CLASS! Can anyone tell me whats wrong with this config.....
Look closely,
Cause I sure as hell didn't.
auto bond0.3
iface bond0.3 inet static
        vlan-raw-device bond0
Okay I will narrow it down.
Now what will make local network connectivity possible but wont allow you
to reach remote networks.
A. Mac address tables in a switch not showing your IP until power cycled..
B. Improper bond (link aggregation) setup in config file...
   yeah that could probably do it.
I went through it for a bit trying to figure this one out. I learned
quite a bit and I was able to recall my recent CCENT studies with
this problem also. Which made me feel kinda good. This is for my clone
server which i dusted off for a project that needs to be completed and
for future projects also if they come about. I added a two more interfaces
to the bond0 interface and changed the interface's IP to my current
network setup. I thought all was good till i just could not get access 
when doing updates. It took a bit of back and forth but I just sat down 
and read through the conf and there it was. The darn gateway option was 
commented out. SIGH! Well i did some pretty good trouble shooting and 
sharpened my deduction skills like a regular slueth, "I say my dear 
Watson I think I figured this one out." Needless to say this was a rookie 
mistake and should have been apparent when I saw this.
root@clone0:~# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface      *        U     0      0        0 bond0.3     *        U     0      0        0 bond0.6
No default route. SIGH...again. Sometimes you get caught up in the more 
advance stuff and forget about the fundamentals. Not only layer 1 but 
configuration. Here is how its suppose to look.
root@clone0:~# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface      *        U     0      0        0 bond0.3     *        U     0      0        0 bond0.6
default         UG    100    0        0 bond0.3
Either way the box is back up and ready to image and restore. Once I 
finish the original I will clone the system accordingly. The clone server 
is an older HP server with 10k and 15k U320 SCSI drives in RAID 10. So it 
can do imaging/restoring pretty fast even when running the array at only 
10k since that's the slowest disk speed. It also has 4Gb of ECC RAM and 
two Dual core Intel Xeon Processors running at 2.4 GHz. I have tested it 
before and it does its job very well. I like re-purposing older servers 
and giving them new task. Sometimes these waste machines produces by not 
being recycled or re-purposed doesn't make sense.
Aight time for some sleep I will have nightmares about #s now. :(