Learn the essential functions of CompTIA Security+, which establishes the core knowledge required of any cybersecurity role and leads professionals into intermediate-level cybersecurity jobs.
TCP/IP
11K
Solutions
17K
Contributors
Transmission Control Protocol/Internet Protocol (TCP/IP) is the set of networking protocols that define end-to-end connectivity specifying how data should be packeted, addressed, transmitted, routed and received at the destination. This functionality is organized into four abstraction layers which are used to sort all related protocols according to the scope of networking involved.
Share tech news, updates, or what's on your mind.
Sometimes clients can lose connectivity with the Lotus Notes Domino Server, but there's not always an obvious answer as to why it happens. Read this article to follow one of the first experiences I had with Lotus Notes on a client's machine, my now good bipolar friendly software.
0 Comments
Configuring network clients can be a chore, especially if there are a large number of them or a lot of itinerant users. DHCP dynamically manages this process, much to the relief of users and administrators alike!
Active today
One note:
the DHCP server should also update the DNS server (& reverse zone) with issued addresses & names as well as remove them again when a lease expires.. (This only requires DHCP servers have update access to the DNS servers).
This is done slightly different in windows world there all systems have the right to put anything they like in the DNS. (and Not remove stale records).
One Caution but it maybe be beyond the scope of this article
Don't use multiple DHCP servers / network segment without understanding how it really works first.
the DHCP server should also update the DNS server (& reverse zone) with issued addresses & names as well as remove them again when a lease expires.. (This only requires DHCP servers have update access to the DNS servers).
This is done slightly different in windows world there all systems have the right to put anything they like in the DNS. (and Not remove stale records).
One Caution but it maybe be beyond the scope of this article
Don't use multiple DHCP servers / network segment without understanding how it really works first.
Creating an OSPF network that automatically (dynamically) reroutes network traffic over other connections to prevent network downtime.
Network ports are the threads that hold network communication together. They are an essential part of networking that can be easily ignore or misunderstood, my goals is to show those who don't have a strong network foundation how network ports operate.
The Maximum Segment size (MSS) is an important consideration when troubleshooting connectivity via the Internet/Intranet. As the packets are routed via the Internet/Intranet, the packets must traverse through multiple routers in the path between two hosts. In a perfect world, each TCP segment can pass through every router without being fragmented. If the segment size is too large for any of the routers through which the data traverses, the segments that are too large must be fragmented. For most End-Users, the MSS is set automatically by the operating system, but as you will see in the article, a router/firewall can modify the packet and change the MSS. The MSS is easily calculated from just a few known variables; you can use this information to predict what data packets would look like once they were captured from such as TCPDUMP or Wireshark.
A few weeks ago I encountered a very interesting issue while capturing data with tcpdump in my lab for a research project that I was working; the affects of IPv4 packet exchange between two hosts. What I observed was the MSS in the original packet that was transmitted from host A to host B was being modified; I expected the MSS of the initial SYN packet from host A to be 1460 and the SYN ACK packet from Host B to be 1460. This however, was not the case as I had observed the MSS on the initial SYN packet from Host A as 1350 when sending a packet to Host B utilizing TCP on port 80:
1. Host A SYN bit sent with MSS of 1460
2. SYN …
A few weeks ago I encountered a very interesting issue while capturing data with tcpdump in my lab for a research project that I was working; the affects of IPv4 packet exchange between two hosts. What I observed was the MSS in the original packet that was transmitted from host A to host B was being modified; I expected the MSS of the initial SYN packet from host A to be 1460 and the SYN ACK packet from Host B to be 1460. This however, was not the case as I had observed the MSS on the initial SYN packet from Host A as 1350 when sending a packet to Host B utilizing TCP on port 80:
1. Host A SYN bit sent with MSS of 1460
2. SYN …
TCP/IP
11K
Solutions
17K
Contributors
Transmission Control Protocol/Internet Protocol (TCP/IP) is the set of networking protocols that define end-to-end connectivity specifying how data should be packeted, addressed, transmitted, routed and received at the destination. This functionality is organized into four abstraction layers which are used to sort all related protocols according to the scope of networking involved.
Top Experts In
TCP/IP
