Cisco Network part 83

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Cisco Network part 83

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Nội dung Text: Cisco Network part 83

  1. clockrate 64000 frame-relay intf-type dce In the config below, the 102 is the DLCI that will be presented to the router connected to this - S0 - interface. 201 is the DLCI that is mapped to S1 frame-relay route 102 interface Serial1 201 frame-relay route 103 interface Serial2 301 interface Serial1 no ip address no keepalive encapsulation frame-relay clockrate 64000 frame-relay intf-type dce frame-relay route 201 interface Serial0 102 frame-relay route 203 interface Serial2 302 interface Serial2 no ip address no keepalive encapsulation frame-relay clockrate 64000 frame-relay intf-type dce frame-relay route 301 interface Serial0 103 frame-relay route 302 interface Serial1 203 ________ ______ | FR SW |_S2______S0_| R3 | |_______ | |______| S0 / \ S1 / \ / \ S0 __/___ _\_S0__ | R1 | | R2 | |_____| |_______| R1 S0, R2 S0 and R3 S0 will be on the same subnet. You can treat it as p2mp. I put all the DCE ends of the cables on the Frame Switch, so clock rate is defined there. However, this is not a requirement. The FR Switch router does not need to have the DCE end. Regardless of the gender of the cable, however, the "frame- relay intf-type dce" is required. I defined the DLCIs as Source Router + 0 + Destination Router. So if the circuit goes from R1 to R3 it's DLCI 103. From R3 to R1 it's DLCI 301.
  2. ****************************************************************** ******** From: Question 22 Subject: What are the different types of memory used by Cisco Routers? The 2500 Series and 7204 VXR have the same types of memory, but they are implemented in different physical packages: ROMMON - This is the initial bootstrap for the router. Boot Helper - This is a subset of IOS that is used to update software or network boot. The 2500 implements the ROMMON and boot helper in a set of two ROMs. The 7204VXR has ROMMON in a ROM and boot helper in a piece of flash memory on the I/O controller called boot flash. Main memory - This is used to hold routing tables, and IOS variables. In the 7204 VXR, IOS itself is also resident in main memory. The 2500 Series usually runs the IOS directly in flash. Shared memory - This is the memory that holds packet buffers. On the 2500 Series, this is part of the same physical memory as main memory. On the 7204 VXR, it's separate memory. Flash memory - This memory holds the IOS image. On the 2500 Series, there are two flash SIMM sockets (max 16 MB). On the 7204VXR, there are PCMCIA slots on the I/O controller which can take a 128 MB flash disk. Configuration memory (NVRAM) - This is the memory that holds the IOS configuration. In the 2500 Series, it's a 32 KB EEPROM. On the 7204VXR it is 128 KB battery backed up SRAM on the I/O controller. ****************************************************************** ******** From: Question 23 Subject: How do I load the Documentation CD (UniverseCD) on Windows 2000? Doc CD Content appears garbled: The Doc CD content is compressed - it requires Verity to decompress it. This is why Verity is used on the Doc CD. What has happened is you've tried to directly open up index.html off the CD into your browser, and this is not possible todo. The CD must be accessed through the Verity Web Publisher through: This is the startup address that is launched when you click on "Launch CD." Windows 2000 and Doc CD: Pre-July 2000 Documentation CDs do not work on Windows 2000 out of the box. They will cause "Search.exe" to crash when run under Win2k. There is a fix that sometimes works for these CDs at:
  3. This fix MUST be done BEFORE you install the CD. If the CD has already been installed, then uninstall it, delete c:\cisco, make this registry change, then re-install the Doc CD.(both the Browser Software Installer and The Documentation CD (I have tried this on My labtop which is running windows 2000 and it worked fine but I had to delete c:\Cisco first and Lunch the Browers software Installer CD (1) first then the Document CD(2) (my version of CD was Nov 1999) (I have already sent this one to you did you delete c:\Cisco and lunch both CDs) Other fixs are shown The Doc CD starts up to about:blank There are two alternate fixes for this: 1. After launching the Doc CD, put in for the address, and then add it to your favorites. - or - 2. This is a 4-step fix: A. Ensure that search.exe is not running. B. Edit the installed search.ini (c:\CISCO\search.ini). C. Change the line 'Browser=c:\program files\internet explorer\iexplore.exe' to 'Browser=msie' D. Launch the CD. Nothing happens when I click Launch CD The usual cause for this is that you've installed a post-July 2000 Documentation CD over the top of a previous Doc CD. The fix for this is to: 1. Uninstall the Doc CD from the control panel->add/remove programs. 2. Delete c:\cisco 3. Reinstall the Doc CD. Finally to reorder a CD The Cisco Documentation CD is also available online at: ****************************************************************** ******** From: Question 24 Subject: How dow I load a large image on a 2500 *lab* router? For production work (support by Cisco required) you need 16M Flash to run 12.0 or 12.1 Enterprise. If you don't need Cisco support, 12.0 Enterprise is small enough (about 10M) to run from RAM (upgrading to 16M of RAM is MUCH cheaper than upgrading to 16M of flash) using a compressed image in the 8M of flash you do have.
  4. 12.1 Enterprise is 14M so it must be run from flash (otherwise there is not enough RAM remaining to even complete loading of the OS). Check the release notes on for the IOS release you want to use. If the actual size of the IOS plus the minimum recommended RAM totals less than 16MB, you can run compressed or boot from TFTP without expanding flash. Check deja-news on google if you are unclear on how to run a compressed image on the 2500, it is a frequent request and hopefully will turn up in the renovated FAQ when Hansang gets a chance to publish it. ****************************************************************** ******** From: Question 25 Subject: daisy-chaining reverse telnet console-aux ports > I've hooked 4 routers together in a lab and I'm daisy-chaining them > aux --> console and using reverse telnet to get to them... > > However when I get to the fourth router and do a CTRL-SHFT-6 X, > I get back to the first router. If I kill the AUX line, then initiate the > reverse telnet again, I fall through router 2 and 3 to 4 again... > Is there an easy way to fall back one router at a time? > or should I not bother to do this? You have two options. One is to use a different escape character on the second (third, fourth etc) console (and/or vty) conf t line con 0 /* or vyt 0 4 */ escape-character 23 This will let you use CTRL-W then X to break out reverse telnet. Or You can use CTRL-SHFT-6, CTRL-SHFT-6, X to come back to the second session, and CTRL-SHFT-6, CTRL-SHFT-6, CTRL-SHFT-6, X to come back to the third session, etc. ****************************************************************** ******** From: Question 26 Subject: How do I setup Lock & Key ACL? Or punch temporary holes in my ACL if someone authenticates to my router? username foobar password cisco int s0 ip address ip access-group 101 in
  5. /* or port 22 for ssh */ access-list 101 permit tcp any host eq telnet access-list 101 dynamic foobar permit ip any any line vty 0 2 login local autocommand access-enable host timeout 5 line vty 3 4 login local rotary 1 The first access list allows telnet into the router. Your users will telnet into router and authenticate with username foobar and password "cisco" The router will then immediately disconnect the telnet session. When they successfully authenticate, an access list with their source IP will be added to the dynamic list. Basically, if they authenticate correctly, they can come in to the inside network. After 5 mins of inactivty the entry will be deleted from the access list. The vty 3 and 4 are using the rotary command so that you can telnet to your router with the command: "telnet 3001" This takes you to vty 3 (or 4). This way, you can telnet into the router and actually manage it. A very subtle but VERY important point. If you forget this, you'll be making a trip to use the console port. ****************************************************************** ******* From: Question 27 Subject: How do I telnet to a specific VTY line? See "rotary" example in question 48. ****************************************************************** ******** From: Question 28 Subject: Is there a better (free) tftp server than the one by Cisco? file located at: ****************************************************************** ******** From: Question 28 Subject: How do I NAT on a single Cisco 2503 Ethernet interface interface Loopback0 ip address ip nat inside interface Ethernet0 ip address secondary
  6. ip address xxx.yyy.zzz.ttt ip nat outside
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