Below you'll find a list of all posts that have been tagged as “CISCO”
When you have to protect your VoIP CallManager in a secure zone of your lan you have to face two problem: SIP and NAT. In our case we handle voip sessions through firewall by configuring an ACL with TCP/UDP port_set. For internal resources, we don’t use NAT mode, here you have the ports from phones to CM: Destinaton port Description …
Once upon a time there was a Cisco switch called CatOS, it had the power to transform its ports into a layer3 links, But it had a secret … vlan tale …and yes the secret is this: This conf command! You can find him in CatOS and on more recent IOS Cisco firmware. When we configure a routed-port on a …
AS-PATH prepending stand for announce my prefix with a low priority. This technique, in a multihomed BGP scenario, it is used to lighten the traffic coming from a peer. The BGP route selection process prefer prefix with a short AS-PATH instead a long AS-PATH. FIRST create an ACL to select your source prefix the traffic to prepend: SECOND create a …
IEEE 802.3ad is used to aggregate multiple link ethernet for increase the network speed and availability.You can configure Layer3 to Layer3 LACP or Layer2 to Layer2 Etherchannel, but sometimes you have to do more: Some routers like Huawei 2240 are only configurable in LACP Layer 3 mode but, for design requirements, the Core Switch (ex.: Cisco) have to be set …
It is sometimes possible to meet a multi-vendor and multi-client environment. For VoIP networks is not good but happen. A Network Admin can automate switch configuration in order to not provide the configuration of each individual phone and allow the voip team to install the devices by themselves. In this example we have an HP A5130 switch a CISCO IP …
OSPF is a king routing protocol that speaks on Multicast addresses 224.0.0.5 and 224.0.0.6. Once the neighborhood relationship is installed and LSAs are exchanged, the SPF algorithm starts running. If the new OSPF peer is a malicious router it can cause a lot of damage to your routing table such as: Network congestions Dos attacks Loops LSA flooding and why …
JunOS IOS show chassis environment show environment show system processes show processes cpu request support information show tech show system connections show tcp show configuration show running config monitor start messages terminal monitor monitor stop terminal no monitor show chassis environment show environment all show interface terse show ip interface brief show log messages show logging show multicast route sh …
When you try to connect via Port Channeling Catalyst and HPE switches you should choose the same Link Aggregation protocol. HPE speak LACP, Cisco as a native language speaks PAGP but gets along well with LACP. To activate LACP under Cisco interface you have to usechannel-group [n] mode active command. HPE use instead link-aggregation mode dynamic under Bridge-Aggregation interface. bye! …
show interface is maybe the most famous command that is entered when we start troubleshooting.Interpreting the output of this command is like reading the results of the blood analysis, some results are easy to understand, while others are very cryptic but very useful to take us to another level of troubleshooting! Let’s see runts, giants an throttles: RUNTS are frames …
Little conf to enable usefull SNMP Traps on Cisco Catalyst: bye .glitchlist crew