Linux · Summary

Linux tc-how to work on different IPs

#!/bin/bash interface=eth0 ip1= ip2= delay1=100ms delay2=200ms tc qdisc add dev $interface root handle 1: prio tc qdisc add dev $interface parent 1:1 netem delay $delay1 10ms 25% tc filter add dev $interface parent 1: protocol ip prio 1 u32 match ip dst $ip1 flowid 1:1 tc qdisc add dev $interface parent 1:2 netem delay $delay2… Continue reading Linux tc-how to work on different IPs

python · Summary

Python: OverflowError: signed char is greater than maximum

Here the pseudo code about the flow: It runs into the error: with a special character ‘À’  which its binary value is 192 My way to resolve this error is to update typecode of the array from ‘b’ (signed char) to ‘B’ (unsigned char). Reason: Data from the file should not in a range which from… Continue reading Python: OverflowError: signed char is greater than maximum

Cisco · Juniper · Network · Summary

Difference of SNMP get route entry[forward-MIB] between Cisco and Juniper

Cisco设备,通过snmp walk (route table)节点获取设备路由 Juniper设备,通过snmp walk节点获取路由 后遇到Cisco 7609 (12.0 IOS),及Cisco IOS 15.2版本的3560通过1.获取路由时失败,SNMP walk获取成功,但是通过Juniper方式使用1. + network address (as index) 的SNMP Get单条时获取失败;反复尝试后发现 Cisco  SNMP get route entry 需要使用 + network address + net mask 时设备都有值返回。

Linux · Summary

Linux session number/timeout setting

在Cisco设备中可以通过: line vty 0 number 配置设备CLI(Telnet/SSH)登陆的session数 line vty下通过 exec–timeout minutes seconds 配置设备session的超时时间。 本文介绍在Linux中如何实现以上机制(1、2通过SUSE/CentOS 内核2.6.32:验证通过)。 1. Linux Telnet session数限制 借鉴: 的内容  使用文本编辑器配置xinetd.conf文件: vi /etc/xinetd.conf 修改instances参数完成配置 defaults { instances = 60 //修改此数字 log_type = SYSLOG authpriv log_on_success = HOST PID log_on_failure = HOST cps = 25 30 } 修改完成后,通过 service xinetd restart 或 /etc/init.d/xinetd restart 重启 xinetd服务使配置生效。 2. Linux… Continue reading Linux session number/timeout setting


SNMP simulator installation guide

Introduction The SNMP Simulator software is intended for testing SNMP Managers against a large number of SNMP Agents that represent a potentially very large network populated with different kinds of SNMP-capable devices. More info refers to its official website This blog is about how to install SNMP Simulator on windows (Info about my OS :Win10… Continue reading SNMP simulator installation guide