Networking Knowledge Base

Core issueThe casuser does not have sufficient privileges to access Windows DLLs. The dynamic link library dbencrypt.dll could not be found in this specified path:  avloader.exe - Unable to Locate DLL  The dynamic link library dbeng.dll could not be ...

Core IssueNetwork Address Translation (NAT) replaces IP addresses within a packet with different IP addresses. NAT is very useful in these instances:Conserving IP address spaceConnecting a private network using an unregistered address to a public net...

ResolutionWhen a device on your network is assigned an IP address that is on the same subnet as another device on the Internet or external network, the result is overlapping networks.This is a common result when two companies merge together.  It is p...

IntroductionSNMP is an application-layer protocol that provides a message format for communication between SNMP managers and agents. A security model is an authentication strategy that is set up for a user and the group in which the user resides. A s...

Core IssueA Cisco router can be configured for routing specific protocols and bridging other protocols at the same time. The Concurrent Routing and Bridging (CRB) feature allows a specific protocol to be routed on certain interfaces and bridged on ot...

Core issueThis message indicates that the process is unable to find a large enough block of contiguous memory. The IP Input process attempts to get 1028 bytes from the processor pool of memory, as shown in this example:%SYS-2-MALLOCFAIL: Memory alloc...

Introduction:Configuring port security on Catalyst switches running CatOS:Related Information: Introduction:Port security is easy to configured and it allows you to secure access to a port based upon a MAC address basis.Port security can also configu...

Core issueThis is an expected behavior as you apply the Quality of Service (QoS) on the physical interfaces that make up the EtherChannel. Since the commands get applied line-by-line, the port channel sees the ports mismatched at different instances ...

Core IssueThe network modules for the 2600, 3600, and 3700 series routers sometimes require a certain Cisco IOS  Software feature set in order to be recognized. ATM, voice, and switch modules require a Plus feature set, and Virtual Private Network (V...

ResolutionInstead of copying to configuration in enable prompt, copy the configuration in the global configuration mode.When creating a configuration file, you must list commands logically so that the system can respond appropriately. To accomplish t...

Core issueThe PAGP logging facility reports events that involve the Port Aggregation Protocol (PAgP). PAgP is a protocol used to negotiate EtherChannel links between switches. The switch generates the %PAGP-5-PORTTOSTP or %ETHC-5-PORTTOSTP syslog mes...

Core issueThis can be required in a scenario where you use third party IP phones that draw too much PoE. Hence, if there is a show or debug command that can be done to see real-time data or data averaged over a certain period of time on the power con...

Core IssueThis is due to a lack of available memory caused by insufficient physical memory or a memory leak.ResolutionIf no output is produced when the show run command is issued, perform the following steps:Issue the show memory [summary] command to...

Core issueThe message looks similar to this:%SECURITY-1-PORTSHUTDOWN: Port [dec]/[dec] shutdown due to [chars] This message indicates that a port has been shut down due to an insecure host sourcing a packet into that port. [dec]/[dec] is the module n...

Core issueThe 1400 W DC multi-input supply cannot be used with other power supply types. However,  other power supplies in this product line work with the other types during an upgrade.ResolutionIf you mix power supplies in a Catalyst 4500 series cha...