ASA 8.3(2) is out, as is ASDM 6.3(3)
I got off my ass tonight and decided to update the ASA (yes, my licensing is correct!). I haven't had a chance to play with it a while lot (you can see it's only been up for 3 and a half hours), but it seems pretty cool. I sat down and read the release notes for 8.3(2) and there's a few things you should know. First off, you're going to need more memory. Well, if you look at mine, you can see I've maxed out what the thing will accept, so I'm perfectly safe; but chances are, you're not. Cisco has a nice table to let you know what your memory needs are. In fact, if you head over to this web page, you check out the release notes for both 8.3(1) and 8.3(2). You'll see the new features as well as caveats fixed with these versions. Now that I have informed all you guys about the upgrade, I'm going to start playing with it for a little bit before the sun comes up and kills me. Dammit! It's already 1am!
Port Forwarding on the Cisco ASA in 8.3 from the ASDM made easy
In my last post I taught you how to forward a port on the ASA 5505 running version 8.3 from the CLI. Some of you prefer to use the ASDM to do you changes, so I guess I'll show you how to do it from there. The ASDM is a bit of a learning curve for someone that's used to the CLI, and most CLI guys hate a GUI with a great passion. I can go either way. I use the ASDM to make some changes simply because I want to learn it and there's some guys coming into the field today that were taught on the GUI rather than a command line.
In this lesson I'm using ASDM version 6.3(1) and ASA version 8.3(1). Since we added a web server in the last post, let's make this one an FTP server. The FTP server's IP is the same as the web server, 10.9.8.7/24 and we're running over the standard FTP port, 21.
First off, we want to start up the ASDM and connect to the ASA. Once there, click on the 
button at the top of the screen, then the 
button near the bottom left, and finally select 
near the top left. You'll now be at a screen that looks something like this:
Click for larger version
Now we need to create a new object, so click on "Add" under Addresses, then "Network Object".
Now we need to fill out our new window. Once you fill out the name, IP address and description, you need to drop down the NAT box and fill it out. Click the "Add Automatic Address Translation Rules" box, leave the type as "static" and set the translated address as the outside interface.
We now need to go to the Advanced menu from the Add Network Object window and setup the port forwarding. The source will be inside, destination is outside. Protocol in this instance is TCP and our port is 21, both real and mapped.
Click "OK" twice and your object will be created as well as the port forward. Now we just need to add the access rule. On the left side of the screen, just above the NAT Rules is your Access Rules. From there we want to click "Add" and "Access Rule".
We need to create the rule on the outside interface, coming from any IP to the FTPServer using FTP as the service.
Once you click OK, your rule is added. You don't have to add a description like I did in the image above this one, I just did that for the hell of it. When you click "Apply" at the bottom of the screen, the ASDM will issue the commands to the ASA. I have preview turned on, so I can always see what commands are being sent to the device before they are actually sent. If you followed all the steps above and you have preview turned on, you'll see the following:
And you'll notice that those are the exact 4 commands that I gave in the last post about doing it from the CLI! Now you can forward any port you want from either the CLI or the ASDM!
On a side note, I know a lot of guys hate the ASDM. When I was writing this post and going through all of this I was kinda upset when I saw that I had 10 pictures for 4 lines of code. The good thing about the ASDM is that you have everything right there at your disposal and you really don't need to know the vernacular of IOS. The drawback is that it will take you longer to get things done at first, but once you get used to it, it can be just as fast.
Port Forwarding on the Cisco ASA in 8.3 from the CLI made easy
So it's been a month and a half since I posted an update, and it's 4:15 am right now. I can't sleep and I found out there's another networking blog out there using the same WP theme as me, so I figured I better put something up here since it was fresh in my mind. Well, now that the niceties are out of the way, let's get to work.
I recently added an ASA 5505 to my home network at the edge. Obviously, when I did, all of my port forwards went to hell because the ASA is now blocking everything. I run a web server on one of my servers here and I like to be able to access it because I keep a lot of tech manuals and other stuff on there. Well, I went about trying to set up port forwarding the old way and learned real quick that this pops up when I do:
ERROR: This syntax of nat command has been deprecated.
Please refer to "help nat" command for more details.
Yeah, that sucks. On the new version of the ASA OS, global has gone the way of the dodo. I did a bunch of searches on Google to figure it out and everything I ran across was very hard to decipher. That's why I'm writing this. You can setup a port forward in 4 quick and easy steps. Just change the things that are underlined to fit your network and you'll be just fine.
In this example, we want to be able to access a web server behind the firewall. We'll assume you are using the standard HTTP port, the web server's internal IP address is 10.9.8.7/24, and that you at least know what you're doing enough to be configuring an ASA in the first place. I'll give you the steps, then I'll explain.
Step 1: Create a new object group for you web server.
asa5505(config)# object network Webserver
Step 2: Add the IP of the web server to the network group.
asa5505(config-network-object)# host 10.9.8.7
Step 3: Forward the port via the NAT command.
asa5505(config-network-object)# nat (inside,outside) static interface service tcp www www
Step 4: Exit back to the root and add the access list
asa5505(config)# access-list outside_access_in permit tcp any object Webserver eq www
That's it! Now, let's explain what's going on here. Cisco has started moving more and more towards use of object groups in their configs. It makes things easier, especially when you have a situation where you have 20 web servers behind the firewall and you want to add 1 more in. Rather than having to rewrite a whole bunch of ACL's, you just add the IP of the new web server into the object group and everything is done for you. After you create the object group (in this instance a network object, you can also create service objects), you add the IP of the specific object (or objects) that you want to point to. So here our web server is 10.9.8.7. If you want to send port 80 to more than 1 IP on your internal network, just add more IP's to that object group.
Now is the fun part. While we're in the object group, we need to NAT port 80 only to that specific object group, hence you're still at "asa5505(config-network-object)#" prompt. Now type "end" to get back to the regular config terminal and we need to open that port in the ACL. Yes, www = 80. You can type either one and you get the same result. If I have to go through and explain NAT, how it works and why I enter in that specific command to forward the port, then there's a possibility that I'd need to send you an invoice for my time because we would be here for a while.
This works for ANY port forward. If you want to RDP into a machine, simply replace port 80 (all those www's you see up there) with 3389. There is one caveat. You can only do one port forward per object group. So let's say that our web server is also an FTP server and you want port 21 to forward as well as port 80. You're going to have to create a whole new object group (object network FTPServer), put the same IP in the group (host 10.9.8.7), do the nat command again (nat (inside,outside) static interface service tcp ftp ftp), exit back to the root of config, and add the access list (access-list outside_access_in permit tcp any object FTPServer eq ftp).
This should get you up and running with you port forwards in no time flat. It is a bit of a pain in the ass to have to create a new object group for every port you want to forward, and maybe there's someone out there that's reading this right now thinking "dude, you don't have to create more than one group! You can just do...". Well, you need to enlighten the world with this knowledge and post it in the comments section. And if you're too scared to do so, shoot me an email to greg(at)gregledet(dot)net.
I'd also like to thank Stefan Fouant for an excellent class today on JUNOS Switching. I learned a lot in his class and you can learn a lot from his website. Check it out and tell him Greg sent ya!
I shall call it “Mini-Lab”
I felt like putting something together here at the house to replace what I lost in the hurricanes. This may have been a Hurricane blog for a short time, but first and foremost it's a Network blog. I now present to you... Mini-Lab.
Front of Mini-Lab
Back of Mini-Lab
The 4500M actually has 2 NP-6E's in it (6 Ethernet Ports each). It's a work in progress, and I'll defidently be adding on to it, but this is just what I could get my hands on at the present time. Hell, I may even open it op to some of you guys that are working on their CCNA's and stuff to give you a little rack time. Just to break it down, here's what you're looking at:
Cisco uBR924 Cable Modem / Router. Actually supports H.323 voice too
2 x Cisco Catalyst 2924XL-EN switches. Need to move packets somehow!
Cisco 2620 Router. With WIC-1DSU-T1.
Cisco 3620 Router. With 2E-2W and WIC-1DSU-T1
Cisco 4500M Router. With 2 NP-6E's. We used these when I was working for an ISP. Real monsters back in the day
Like I said, it's a work in progress. I hope to really build this rack up and make it quite the monster. I'm looking into getting a 2821 to do VoIP with along with a 3560-12 PoE and a couple 7690's. It should be sweet!
Daylight savings time in the US and NTP servers.
Here's how you want to set Daylight savings time in the US. If you haven't done so already, I'm sure your logs may be a little out of wack. Remember to add your correct time-zone to this, as I'm using Eastern.
Router(config)# clock timezone EST -5
Router(config)# clock summer-time EDT recurring 2 Sunday March 02:00 1 Sunday November 02:00 60
Now, let's explain. What you are doing here is starting by telling your device that you want to set your normal time-zone as Eastern Standard Time with an offset from UTC as -5 Hours. Then you're going to configure "summer-time" or daylight savings time. "EDT" is the word used for Eastern Daylight Time. I'm setting it as "recurring" as we have it every year. Then I'm telling it to start on the 2nd Sunday of March at 2:00 AM and to end on the 1st Sunday of November at 2:00 AM with a 60 Minute offset. The US Navy says that these are the proper dates (click here for proof).
While we're at it, let's make sure that our clock is correct. Here's 2 NTP servers I like to add to my configs:
Router(config)# ntp server 149.20.54.20
Router(config)# ntp server 64.73.32.135
The DNS names for these servers are 0.north-america.pool.ntp.org and 1.north-america.pool.ntp.org. You can be pretty sure that they are going to be correct.
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