Hot answers tagged

27

While using a classical RJ45 jack, the connection on your Cisco router really is a RS232 serial connections. This means that, independently from the physical connector, your PC need to speek the same RS232 protocol. This is why do you need a DB9 (classic serial port connector) to RJ45 converter. The converter does not change the underlying protocol, rather ...


24

You should know three things about class-based-routing: Class-based routing was a simpler system that was abandoned (in 1993) long before most people ever heard about the Internet. In all likelihood, nobody you will ever know has used it. And if any of your network equipment is that old, you should seriously consider alternate employment. The system used ...


23

The only people I have ever met who use the terms "Class A/B/C" are people who are using them incorrectly to mean a /8 or a /16 etc (except for just one person who used "Class A" to be the first octet, "Class B" to be the second octet, etc. But he was an idiot who refused to change his phrasing even though it led to so much confusion). So go ahead and learn ...


14

In a word, yes. People will often talk about it in the same way that the course material does. Nobody uses classful networking, or at least nobody I've encountered; during infrastructure/architecture planning people will often say things like "we'll set them up with two class C's here." It's easier than saying "we'll give them a /23" or "172.16.0.0-172.16....


14

Typically, autonomous systems (ASNs) use an IGP (which can be OSPF, IS-IS or iBGP) so routers in their network know how to reach eachother. Networks connected to these routers and reachable through them can be distributed via this IGP as well, but iBGP may be used for that too. ASNs exchange routing information via BGP. Typically, only aggregated prefixes ...


13

I've found a workaround for this problem when there is no access to VPN server settings: set up Teamviewer disconnect RDP connect via Teamviewer connect to VPN in remote session disconnect Teamviewer connect via RDP continue working as used to


13

You would make TFTP access over the internet secure the same way you'd make access to anything over the internet secure. By going through a VPN. Cisco's IP phones can be set up to use a VPN, and someone even put together a handy doc around common issues with this setup that you might want to take a look at.


12

Solved. The issue is with SCCM 2012 SP1, a service called: ConfigMrg Wake-Up Proxy. The 'feature' does not existing SCCM 2012 RTM. Within 4 hours of turning this off within the policy, we saw steady drops in CPU usage. By the time 4 hours was up, ARP usage was merely 1-2%! In summary, this service does MAC address spoofing! Cannot believe how much havoc ...


12

You should be able to connect the console port to the patch panel with a rollover cable. You must use a standard straight-through ethernet on the other end - NOT another rollover cable. If it's viable, it would be much simpler to configure the switch with a management IP and SSH/telnet access.


12

Use a straight through cable from the console port of the Cisco to the patch panel, and then a rollover from the port in the wall to your computer?


10

Then you can't do it. You've rejected another protocol that permits authenticating the requestor (hcsteve's answer) and you've rejected a VPN which would have allowed TFTP to be tunneled through an authenticated service (Hopeless N00b.*'s answer), so you're stuck with stock TFTP. RFC 1350 makes it fairly clear, in section 1, that authentication is not an ...


10

Word to the wise, don't connect a second hand switch to your production network before you wipe and/or re-configure it. Doing so can cause you MAJOR headaches if your network happens to use VTP. Without getting into the gritty details, connecting it could wipe or modify the VTP database used on your network (holding list of VLANs}, and basically cause your ...


9

you need to create an usual text file like connect myvpnhost myloginname mypassword save it as myfile.dat (for example) and then call "%ProgramFiles%\Cisco\Cisco AnyConnect Secure Mobility Client\vpncli.exe" -s < myfile.dat


9

Nope. The Cisco RV110W device you have contains a dedicated WAN port. This is a physical hardware port intended for this purpose. You will not be able to reassign WAN functions to one of the four switch ports. More importantly, equipment damaged in an electrical storm really should not be trusted. You're going to have to replace this router.


8

Connect to your computer via RDP. Create connect.dat file as following, finishing it with extra empty line (must-have requirement, sic!): connect your-VPN-server-here your-username-here your-password-here Then create connect.cmd file as following for /f "tokens=3 delims= " %%G in ('tasklist /FI "IMAGENAME eq tasklist.exe" /NH') do SET RDP_SESSION=%%G ...


8

It means Silicon Switch Processor a high-performance 7000 series router. According to the answer from dtlokee in this Cisco forum, it does stand for SSP. They use the Si for the "silicon switching", I guess it's a bit dated but that is how they would represent a switch doing L3 switching in hardware. Now I think it goes without saying that multilayer ...


8

Cisco 2960 switches pull in cool air from the sides and exhaust to the rear. Depth-wise they are 1/3 to 1/2 rack-depth (depending on exact model switch and rack). This leaves you very few options. If you mount them unmodified backside of the rack just about the entire switch is in the hot zone. That will only be OK if you have cold airflow running on the ...


7

I found a solution to make it work. My work laptop need to be connected to a vpn with cisco any connect . And I wanted to connect to my work laptop using remote desktop to have a better experience with my home PC mouse and keyboard and a bigger screen. I had this error after the VPN was connecting: Vpn establishment capability from a remote desktop is ...


7

First you should probably know about tab completion and the '?' key for online help in IOS. If I'd inherited a new Catalyst, I'd... Google "Password Recovery Catalyst 2900" Connect a Light-Blue Cisco console cable to it. You can make your own, but you'll still need a USB to serial adapter, they're $15 to $20 or so. Follow the instructions to reset the ...


7

VTP is proprietary to Cisco. Juniper implements something similar with GVRP and MVRP (both industry standard protocols). You'll need to look into both of these protocols to determine exactly what you need and how to deploy them though. It's not something that is a quick "everyone can just run this CLI command" thing for these to function properly.


7

I noticed (based on activity lights) that VLAN traffic between two switch ports are being sent to many switch ports. Seriously? That's not how to determine traffic flows. The activity lights could be active for any number of reasons. Because Host 1 and Host 2 are in different VLAN's then they must be in different Layer 3 subnets as well. The only way they ...


7

Figured it out. Slap enter-pssession -computername XXXXXXX in front of this to remotely connect to a system to check. $com = New-Object System.IO.Ports.SerialPort(“COM1”) $com.open() $com.write([char]13) $com.ReadExisting()


7

The purpose of the prefix (and the deprecated netmask) is to define which part of the address space is on link. If a host has the wrong prefix configured, it will not be able to reach all of the addresses on that link (example). So you will need to reconfigure every host which has had its address and prefix manually configured. I recommend you take this ...


6

My fix for a switch like that would be to replace it. If still under warranty send it back to Cisco, otherwise eat the loss and buy a new one. Why? Clearly something is broken when you get malformed packets. That shouldn't happen. And you should be able to factory-reset the equipment. A switch which starts to act up can cause nightmarish network problems. ...


6

You can't map a port on a public IP address to more than one private IP address, it just won't work because how is the router supposed to know which one to go to? If you're using name-based virtual hosts, you could achieve this by sitting a HAProxy instance in-front of the web instances and direct all traffic from the router to the HAProxy instance. On the ...


6

I think what you are looking for is : router# show running-config interface FastEthernet0/1 This will only display the configuration for port Fa0/1. When you are in config mode, you can use the do keyword to call the show command : router(config)# do show running-config interface FastEthernet0/1


6

The combination of switchport access and switch port trunk allowedmakes theswitchport access` configuration a no-op, right? You cannot have a port in access mode and trunk mode unless I am mistaken. Can someone confirm this for me? Not exactly. Let me break down the configuration: interface Port-channel1 switchport access vlan 100 switchport ...


6

In your question's scenario : No. It would either work (meaning that your ports have Auto MDI-X, which is built into Gigabit Ethernet, IIRC) just fine, or not work at all. Which means the cause of your problem is elsewhere.


6

The no setup express command disables the functionality that resets the configuration when the MODE button is held. I suspect this will do what you're looking for.


6

Absolutely. In the TACACS configuration, you can restrict the commands you allow, but you would do better to move that logic into a web application, rather than give your customers direct access into the switches. Simply put, you can create very granular access control using TACACS, but it is very easy to screw-up, and keeping the user-> device -> port -> ...


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