Žilinská univerzita > Fakulta riadenia a informatiky > Katedra informačných sietí

Practical - Cisco, QoS, Routing, RIP, OSPF, Monitoring, WAN, Security, Switching, MPLS, ASA, Multicast

Possible bugs/limitations encountered in Cisco's RIP implementation

  1. Default route origination not working reliably.
  2. Automatic summarization turned on causes major networks to be propagated throughout the RIP domain with a metric of 1.
  3. Using RIPv2 on NBMA hub-and-spoke topology causes the hub router to rewrite the next hop field in the RIPv2 update to the IP address of the spoke router advertising the originalupdate, thereby creating reachability issues

IOS recovery using other Cisco router as the TFTP server and tftpdnld

The students in our labs oftenly delete not just startup configuration but the whole IOS of a router. Then the IOS of the router have to be recovered. There is one way using the COM port, but it takes time (tens of minutes). The second way is to use an another router with the same IOS as the TFTP server.




R1 will serve as the tftp server, R2 we have to recover. Routers are connected back-to-back using the cross cable.

Configuring FIFO queuing on Cisco routers

For configuring FIFO queuing strategy the Cisco IOS does not provide any explicit commands. The main configuration of FIFO on specific interface is done when you will turn off any other queuing method. For example, default queuing method on serial interfaces running at E1 speed and slower is WFQ. To enable FIFO you must first disable WFQ using following command:

router(config-if)#no fair-queue

If other queuing tools is used, you should also disable these too.

Catalyst 2960 - password recovery

Recovering from a Lost or Forgotten Password


The default configuration for the switch allows an end user with physical access to the switch to recover from a lost password by interrupting the boot process during power-on and by entering a new password. These recovery procedures require that you have physical access to the switch.



VLSM (CIDR) Subnet Calculator

Simple web calculator used for computation of the IP subnets through VLSM:


Konfigurácia VPN medzi Cisco ASA a Cisco VPN klient


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Konfigurácia SSH prístupu na Cisco ASA 5510

Konfigurácia SSH prístupu na Cisco ASA 5510 s lokálnou autentifikáciou. Postup si vyžaduje vykonanie viacerých úkonov v následovných krokoch:


1) vytvorenie lokálnych účtov:

pix(config)#username MENO password HESLO privilege LEVEL_0-15


2) nastavenie autentifikácie pre SSH na LOCAL databázu:

pix(config)#aaa authentication ssh console LOCAL


3) vygenerovanie RSA kľúča

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