Cisco Router config alternatives to Cisco SDM (i.e. no Java required)

Question

We have an old Cisco 850 Series router hanging around here and happen to have a need for it temporarily until we get our new Palo-Alto into place.

Now, after I reset it and try to pull up the configuration page at 10.10.10.1 as you would normally in order to configure it, I run into a few problems.

1. The configurator does not recognize Internet Explorer 11 as even being Internet Explorer at all - thinks it is Netscape. So I am forced to use an older version or Firefox (preferabal anyway, I'm just mentioning the issue)
2. The configuratior allows you to sign into the web page, and then launches Java where you sign in a second time. After that it just stops working. I've tried this in several browsers old and new. I still have to try downgrading Java (as proposed here) and seeing if I can get into it that way. Apparently, this is the usual case with Cisco - check out this quote:

Just a silly anecdote...Cisco has a terrible history of causing a necessity for old JREs and it makes it almost impossible to manage several different pieces of equipment at different software versions. They really need to work on this.

It looks like JRE 6 update 11 may do for that (only x86; the x64 isn't reported to work).

Okay, so, even if I can get the configurator running, I don't want to have to normally run an ancient version of Java just to access the router config.

If I can get into the router config once, is there a way to get this router running with some firmware that doesn't depend on Java? I've flashed TP-Links with DD-WRT successfully, but DD-WRT doesn't seem to run on a Cisco 850.

Any advice?

[conclusions]

Although I have marked an answer for this question, I just wanted to share some of my final thoughts, just in case it helps anyone.

We ended up configuring the router via console cable + Putty. This allowed us to do the work without worrying about SDM or Java at all. And my plan is to be able to remotely administer the router via SSH (again through Putty, or a lovely tabbed application called mRemoteNG), again avoiding the Java issue.

However, I also found another nice little tidbit. I have an old Dell running Windows XP laying around that has a console port. I decided to keep it just for configuring devices. It also has Windows 7. I also found the old Cisco disc that came with the router and it allowed me to install SDM on the computer itself, and also installed Java 5. With that, now I have access to the router via console, SSH as well as SDM all on a machine which never needs to be updated. So I can just plug in this box and not have to worry about messing with the configuration of my regular workstation.

Answer 1

The configuratior allows you to sign into the web page, and then launches Java where you sign in a second time. After that it just stops working.

If you're running into java problems, it sounds like you're trying to use Cisco SDM to manage your Cisco 850. Cisco SDM is EOL, and you should use Cisco Configuration Professional instead of SDM. Cisco Configuration Professional supports the 850 series routers.

If I can get into the router config once, is there a way to get this router running with some firmware that doesn't depend on Java? I've flashed TP-Links with DD-WRT successfully, but DD-WRT doesn't seem to run on a Cisco 850.

You're in luck! You don't need Java to access a Cisco router. All you need is telnet or a serial cable... they commonly look like this:

Options:

• You could try to telnet to the router's IP address, although that depends on whether someone previously had telnet configured on the router.
• If you can telnet to the router, but don't know the password, then you'll have to perform password recovery; this is a handy mapping of break sequences for various serial terminal emulators. This method is also useful if you can't telnet to the router.

Answer 2

I've answered a similar question here: https://security.stackexchange.com/questions/52724/cisco-asa5505-asdm-access-issues/52725#52725

The problem you're describing lies with the Java settings of your Windows machine, not the ASA appliance. Change the Java security permissions (under Configure Java > Security) and make an exception to the IP address of the ASA port which was configured to accept the HTTPS connections from the ASDM. Assign a static address to the Windows machine - don't use DHCP - and allow it to access the ASA.

Although the answer referred here was regarding an ASA 55xx appliance (not a newer NGFW), the answer may still be applicable to your device.

Answer 3

If you're looking to upgrade the device's firmware you'll want to telnet into the device or use a console cable as shown above. In most telnet programs you can use zmodem or xmodem in order to facilitate file transfer. The easiest way to transfer to the router is using a TFTP server.

Here is a cisco knowledge base article on how to facilitate this with ROMmon (Most telnet programs will perform similarly):

http://www.cisco.com/c/en/us/support/docs/routers/2600-series-multiservice-platforms/15085-xmodem-generic.html