Free Network Posts

As per Cisco website definition: Control Plane Policing (CoPP) is a Cisco IOS-wide feature designed to allow users to manage the flow of traffic handled by the route processor of their network devices. CoPP is designed to prevent unnecessary traffic from overwhelming the route processor that, if left unabated, could affect system performance. Here’s a sample configuration in applying Control Plane Policing  (CoPP) in Cisco IOS Routers Step1: Create necessary ACLs a. Important services,e.g.NTP,SSH,SNMP   ip access-list extended SSH-ACL  permit…

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Configuring Juniper to authenticate (also including authorization and accounting) to Tacacs+ server 10.10.10.10 – Tacacs+ AAA server 20.20.20.2 –  Loopback IP Juniper: system { host-name JUNIPER-ROUTER1; } authentication-order [ tacplus password ]; root-authentication { encrypted-password “$r00tp44sw0rdh3r3/1”; ## SECRET-DATA } tacplus-server { 10.10.10.10 { secret “$4ut0g3n3r4t3t4c4c5p455w0rd1”; ## SECRET-DATA single-connection; source-address 20.20.20.2; } } accounting { events interactive-commands; destination { tacplus { server { 10.10.10.10 { secret “$4ut0g3n3r4t3t4c4c5p455w0rd2”; ## SECRET-DATA single-connection; source-address 20.20.20.2; } } firewall { family inet { filter FIREWALL-RE…

Juniper

SSH Configuration Examples in  Juniper(JunOS) Here are the configuration examples: whereas: 192.168.100.100 = Jumphost IP (Allowed IP to SSH into the device) system { services { ssh { root-login deny; protocol-version v2; connection-limit 5; rate-limit 5; policy-options { prefix-list PERMIT-SSH { 192.168.100.100/32; } firewall { family inet { filter PROTECT-ENGINE { term PERMIT-SSH { from { source-prefix-list { ALLOWED-IP; } protocol tcp; port [ ssh ]; } then { count PERMIT-SSH; accept; } } term DENY-SSH { from { protocol…

Juniper

Juniper darwin@vMX-1>configure darwin@vMX-1#set system login message “\n*************************************************************************\n       UNAUTHORIZED ACCESS TO THIS DEVICE IS PROHIBITED\n\nYou must have explicit, authorized permission to access or configure this \ndevice.Unauthorized attempts and actions to access or use this system may \nresult in civil and/or criminal penalties.\nAll activities performed on this device are logged and monitored.\n\n*************************************************************************\n\n” darwin@vMX-1#commit As per Juniper website, message can be formatted using these following characters: \n—New line \t—Horizontal tab \’—Single quotation mark \”—Double quotation mark \\—Backslash Sample output:

Juniper

Step1. Configure EXPORTER MAP set services flow-monitoring version9 template NETFLOW_MONITOR template-refresh-rate seconds 15 set services flow-monitoring version9 template NETFLOW_MONITOR option-refresh-rate seconds 15 set services flow-monitoring version9 template NETFLOW_MONITOR ipv4-template Step2. Configure MONITOR MAP set forwarding-options sampling instance NETFLOW_INSTANCE family inet output flow-server 192.168.30.100 port 9991 set forwarding-options sampling instance NETFLOW_INSTANCE family inet output flow-server 192.168.30.100 source-address 192.168.1.100 set forwarding-options sampling instance NETFLOW_INSTANCE family inet output flow-server 192.168.30.100 version9 template NETFLOW_MONITOR set forwarding-options sampling instance NETFLOW_INSTANCE family inet output inline-jflow source-address…

Juniper

Here’s the sample configuration of Netflow in Cisco running IOS and Nexus-OS. Cisco IOS-XR: The NetFlow use these 3 maps to configure Step1. EXPORTER MAP – configure parameters like export destination IP, udp port (only supported transport protocol), source interface IPv4: flow exporter-map NETFLOW-EXPORTER-MAP  version v9   transport udp 9991   source Loopback0   destination 192.168.30.100 IPv6: flow exporter-map IPv6-NETFLOW-EXPORTER-MAP  version v9   transport udp 9991   source Loopback0   destination 192.168.30.100 Note: destination  udp port can be from  <1024-65535>…

Cisco

Taking Cisco’s  Sample Legal Banner message from their Network Security Baseline page. Sample Legal Banner Notification Configuration ! Present a legal notification banner approved by company legal counsel banner login # UNAUTHORIZED ACCESS TO THIS DEVICE IS PROHIBITED You must have explicit, authorized permission to access or configure this device. Unauthorized attempts and actions to access or use this system may result in civil and/or criminal penalties. All activities performed on this device are logged and monitored. # ! Here’s how…

Cisco

Here’s sample firewall configuration in protecting the box and its services. ICMP: ICMP message types are essential for network administration and troubleshooting. There are quite a number of ICMP parameters, you can refer to IANA ICMP Parameters for the list or if you want to learn more details about ICMP can refer to RFC792. Here’s the 4 types I consider useful for troubleshooting and need to be allowed.Type 0 — Echo Reply –> response from target to host Type 8 — Echo Request–>…

Juniper

Why is considered hidden? Because you won’t see it in the command in Cisco Routers Command Line Interface (CLI). Sample output: RP/0/RSP1/CPU0:CORE1#ser? service RP/0/RSP1/CPU0:CORE1#service ?   redundancy  Service Director related commands. Then what it is? service unsupported-transceiver Configuration: Cisco IOS-XE Router1(config)#service unsupported-transceiver Warning: When Cisco determines that a fault or defect can be traced to the use of third-party transceivers installed by a customer or reseller, then, at Cisco’s discretion, Cisco may withhold support under warranty or a Cisco support…

Cisco

Objective: The PBR policy will be removed facing Uplink-Router once it detected that the server is unreachable. Policy-based routing (PBR) is a method used to make routing decisions based on policies. Scenario: Server1 providing web caching to customers for faster web page loading. Since there is route-map in place to route their http/https traffic to the next hop which is Server1, what if this server suddenly goes down?, the expected behaviour is  the customer won’t be able to access websites.…

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