Archive for June, 2008

Cisco DTP Dynamic Trunking Protocol 27 June 2008 at 12:24 pm by admin

Bitmndframes cisco study guides

DTP Dynamic Trunking Protocol

Trunk negotiation is managed by the Dynamic Trunking Protocol (DTP), which is a Cisco proprietary Point-to-Point Protocol.
These various modes are configured using the switchport mode interface command
Switch trunk interfaces support different trunking modes.

  • Access
  • Dynamic desirable (default mode on Catalyst 2950 and 3550)
  • Dynamic auto
  • Trunk
  • Non-negotiate
  • dotq-tunnel (Not an option on the Catalyst 2950.)

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Tags: wan, cisco, switch, vtp, 802.1q, ip

+ Setting up a Home VPN using bitvise SSHD By admin 25 June 2008 at 5:44 pm and have Comments Off

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Using bitvise WinSSHD for secure VPN

Professional-Grade SSH Server

We continue to invest great amounts of effort to make sure we create the best SSH software we can. These are some of the important features that make WinSSHD special:

  • Ease of use : WinSSHD was written specifically for the Windows platform so that it is easy to install and configure. In a regular Windows environment, it will work immediately upon installation with no configuring .
  • Unlimited connections : WinSSHD imposes no limits on the number of users who can connect. It will accept as many simultaneous connections as you need!
  • Windows groups : WinSSHD 4 natively supports configurability through Windows groups. No need to define account settings for each Windows account individually. WinSSHD knows what groups a user is in and, if configured, will use appropriate Windows group settings.
  • Speed : WinSSHD is one of the fastest SSH servers available. With Tunnelier, SFTP file transfer speeds of up to 5 MB/s (megabytes per second) can be obtained.
  • Single sign-on : WinSSHD 4 supports GSSAPI-enabled Kerberos 5 key exchange, as well as NTLM and Kerberos 5 user authentication. This means that, using Tunnelier or another compatible GSSAPI-enabled client, any user in the same Windows domain , or a trusted one, can log into WinSSHD without having to verify the server’s host key fingerprint, and without even having to supply a password! Using Windows group-based settings, the user’s account doesn’t even have to be configured in WinSSHD.
  • Virtual accounts : want to set up an SFTP server with many users, but don’t want to create and manage 1000 Windows accounts? No problem. WinSSHD supports virtual accounts, created in WinSSHD Settings, backed by the identity of one or more Windows accounts. WinSSHD settings for these accounts are also configurable on a virtual group basis.
  • bvterm : in conjunction with our Tunnelier SSH client, WinSSHD provides you with the best console available on the Windows platform. Our bvterm protocol supports the full spectrum of a Windows console’s features: colors, Unicode characters, and large scrollable buffers. Of course, WinSSHD also supports standard protocols such as VT-100 and xterm.
  • Flexibility : most WinSSHD features can be configured individually on a per-account basis from the user-friendly WinSSHD Control Panel. Using our Tunnelier SSH client, the WinSSHD Control Panel can be accessed and configured through the same user-friendly interface from any remote location .
  • Server-side forwarding : with WinSSHD and Tunnelier, a server and multiple clients can be set up so that all port forwarding rules are configured centrally at the server, without requiring any client-side setting updates. The SSH clients only need to be configured once, and port forwarding rules can easily be changed when necessary.
  • Scriptable settings : Using the supplied wcfg utility, all settings can also be configured from a text file, from a script or interactively from the command-line. Settings can also be configured programmatically through the WinsshdCfgManip COM object .
  • Multi-site support : WinSSHD supports multiple simultaneous, independent installations on the same server for customers needing completely separate sites for different groups of users. Multiple WinSSHD versions can run concurrently, installed on separate sites. (A version prior to 4.10 will occupy the ‘default’ site.)

I like to feel secure so i wanted to show you how to setup an encrypted remote connection from anywhere to your home network. I use this to simply transfer files securely or do remote tasks on multiple computers.

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Tags: ip, interface, vlan, 802.1q, guides, vtp

+ VTP VLAN trunking protocol By admin 23 June 2008 at 4:23 pm and have 2 Comments

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What is VTP?

VLAN Trunking Protocol (VTP) is a Cisco proprietary Layer 2 messaging protocol that manages the addition, deletion, and renaming of VLANs on a network-wide basis. Virtual Local Area Network (VLAN) Trunk Protocol (VTP) reduces administration in a switched network. When you configure a new VLAN on one VTP server, the VLAN is distributed through all switches in the domain. This reduces the need to configure the same VLAN everywhere. To do this VTP carries VLAN information to all the switches in a VTP domain. VTP advertisements can be sent over ISL, 802.1q, IEEE 802.10 and LANE trunks. VTP traffic is sent over the management VLAN (VLAN1), so all VLAN trunks must be configured to pass VLAN1. VTP is available on most of the Cisco Catalyst Family products.

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Tags: ip, guides, interface, switch, wan, router

+ Calculating VLSM subnetworks By admin 23 June 2008 at 12:43 pm and have Comments Off

Bitmindframes cisco study guides.

Calculating VLSMs

Scenario: Your company has been given the network address 172.16.32.0/19.

10101100 . 00010000 . 001 00000 . 00000000

After careful planning, looking at current needs and expansion, you realize you need a maximum of three subnets of 1,000 hosts, three subnets of 250 hosts, and several subnets for serial point-to-point links.

There are several ways to do this, but you have decided that you will variably subnet your network as follows: (We did it this way just for the exercise and to keep it somewhat simple.)

Step 1 : The maximum number of hosts any of your subnets will need is 1,000, so you decide to make the initial subnets 172.16.32.0/22. Write out the eight /22 subnets in binary and decimal form:

1. 10101100 . 00010000 . 001 000 00 . 00000000 172.16.32.0/22

2. 10101100 . 00010000 . 001 001 00 . 00000000 172.16.36.0/22

3. 10101100 . 00010000 . 001 010 00 . 00000000 172.16.40.0/22

4. 10101100 . 00010000 . 001 011 00 . 00000000 172.16.44.0/22

5. 10101100 . 00010000 . 001 100 00 . 00000000 172.16.48.0/22

6. 10101100 . 00010000 . 001 101 00 . 00000000 172.16.52.0/22

7. 10101100 . 00010000 . 001 110 00 . 00000000 172.16.56.0/22

8. 10101100 . 00010000 . 001 111 00 . 00000000 172.16.60.0/22

Step 2 : You only need three /22 subnets, so you reserved the first three for those subnets needing 1,000 hosts. Which ones are they?

1. 10101100 . 00010000 . 001 000 00 . 00000000 172.16.32.0/22

2. 10101100 . 00010000 . 001 001 00 . 00000000 172.16.36.0/22

3. 10101100 . 00010000 . 001 010 00 . 00000000 172.16.40.0/22

Step 3 : You decide to sub-subnet the fourth subnet (172.16.44.0/22) for the three subnets each needing 250 hosts. A /24 will work well for this. What are the three /24 sub-subnets you will use?

4. 10101100 . 00010000 . 001 011 00 . 00000000 172.16.44.0/22

4a. 10101100 . 00010000 . 001 011 00 . 00000000 172.16.44.0/24

4b. 10101100 . 00010000 . 001 011 01 . 00000000 172.16.45.0/24

4c. 10101100 . 00010000 . 001 011 10 . 00000000 172.16.46.0/24

4d. 10101100 . 00010000 . 001 011 11 . 00000000 172.16.47.0/24

Step 4 : The last (fourth) of the /24 sub-subnets (172.16.47.0/24), you decide to use for you serial point-to-point links. List the first five /30 sub-sub-subnets (if there is such a term):

4d. 10101100 . 00010000 . 001 011 11 . 00000000 172.16.47.0/24

4d1.10101100 . 00010000 . 001 011 11 . 000000 00 172.16.47.0/30

4d2.10101100 . 00010000 . 001 011 11 . 000001 00 172.16.47.4/30

4d3.10101100 . 00010000 . 001 011 11 . 000010 00 172.16.47.8/30

4d4.10101100 . 00010000 . 001 011 11 . 000011 00 172.16.47.12/30

4d5.10101100 . 00010000 . 001 011 11 . 000100 00 172.16.47.16/30

etc.

4d5.10101100 . 00010000 . 001 011 11 . 111111 00 172.16.47.252/30

Tags: ip, switch, study, interface

+ cisco 802.1q switch trunking By admin 21 June 2008 at 12:24 pm and have Comments Off

Bitmindframes cisco study guides.

TRUNKING
Trunking is Point to point link from a switch to a router or a switch. A trunk link can carry traffic from multiple vlans over a single link allowing vlans to span internetworks.
Cisco supports IEEE 802.1Q trunking on 100/1000 ethernet

What does trunking solve?
Without trunking switches & routers have to be interconnected with a separate link for each VLAN. 4 VLANs require 4 links connecting switches S1 & S2 leaving fewer ports for devices. If S2 was connected to S1 it would be more than 4 ports.

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