Tag: packet

All are by packets

Posted on by lechuck park

From Claude with some prompting
Let me explain this network diagram which illustrates packet processing and various network devices:

  1. Network Components:
  • Internet: Shows L3-L7 packet flowing
  • Router: Handles L3 routing and packet control
  • Firewall/IPS/IDS: Manages L3/L4 base packet control and L7 packet analysis/control
  • Switching: Performs Ethernet(L2/L3) switching and L2/L3 packet control
  • Server/Client: Handles packet send & receive (L1-L7), packet making and analysis
  1. Key Issues:
  • COST Concerns:
    • ALL operations are packet-based
    • Performs L1-L7 packet collecting/analysis/switching/routing
    • Multiple devices perform many duplicates of the same functions (L2, L3-L4 packet collecting/analysis/switching/routing)
  1. Suggested Improvement:
  • Mentioned in “IF Possible” section:
    • Consider aggregating all packets and manipulating them from central controls
    • This could potentially reduce redundancy and improve efficiency
  1. Key Message:
  • There are many types of packet processing devices on the network
  • Redundancy occurs as each device performs similar functions
  • Need to explore possibility of centralized packet management system

The diagram effectively highlights the complexity and redundancy in modern network architecture while suggesting a potential path toward more efficient packet processing through centralization.

This visualization emphasizes how current network infrastructure might benefit from consolidation of packet processing functions to reduce duplicated efforts and potentially lower costs.

Traceroute

Posted on by lechuck park

From Claude with some prompting
This image explains the concept of “Traceroute: First Send, First Return?” for the traceroute utility in computer networking. Traceroute sends IP packets with increasing Time-to-Live (TTL) values, starting from TTL=1, 2, 3, and so on. When the TTL reaches 0 at a network hop, that hop returns an ICMP (Internet Control Message Protocol) message back to the source.

However, the order in which the response packets are received at the source may differ from the order in which they were sent, primarily due to two reasons:

  1. Generation of ICMP response packets is a CPU task, and it can be delayed due to CPU settings or other processing priorities, causing a delay in the response.
  2. The ICMP response packets can take multiple paths to return to the source, as indicated by the text “Packet replies can use multiple paths” in the image. This means that responses can arrive at different times depending on the route taken.

As a result, when analyzing traceroute results, it is essential to consider not only the TTL sequence to determine the network hops but also factors like response times and paths taken by the responses.

The potential delay in ICMP packet generation by the CPU and the use of multiple return paths can cause the actual response order to differ from the sending order in traceroute.

Understanding that the response order may not strictly follow the sending order due to CPU processing delays and the use of multiple return paths is crucial when interpreting traceroute results.

Casting packet

Posted on by lechuck park

from Claude with some prompting
This image illustrates the different types of network communication methods: Unicast, Multicast, Broadcast, and Anycast. Each method is represented by a visual diagram showing how data is transmitted from a source to specific targets or groups of targets within a network.

Unicast targets a specific IP address, sending data to a single destination. Multicast targets a specific IP group within one network, allowing data to be sent to multiple recipients simultaneously. Broadcast targets all IP addresses within a specific network, essentially sending data to every device on that network.

Anycast is slightly different, targeting a specific address but sending the data to the closest/nearest device with that address, as determined by the routing protocols and BGP (Border Gateway Protocol) peering.

The image provides a clear visual representation of these communication methods and their differences in terms of targeting and data distribution within networks.