Implement ICMP/ICMPv6 unicast and multicast framework for network lab

[Copilot]

Complete the framework for sending ICMP/ICMPv6 Echo Request packets in both unicast and multicast modes, including IP validation, MAC address conversion, and checksum calculation per RFC 792/4443/1071.

Implementation

IP Address Validation

• validate_ip(): Detects IPv4/IPv6 using socket.inet_pton()
• is_unicast_address(): Validates IPv4 (1.0.0.0-223.255.255.255) and IPv6 (2000::/3) ranges
• is_multicast_address(): Validates IPv4 (224.0.0.0-239.255.255.255) and IPv6 (FF00::/8) ranges

MAC Address Conversion

• ipv4_multicast_to_mac(): Maps to 01:00:5E + lower 23 bits of IP
• ipv6_multicast_to_mac(): Maps to 33:33 + lower 32 bits of IP

Packet Construction

• calculate_checksum(): Internet checksum per RFC 1071
• create_ipv6_pseudo_header(): Constructs pseudo-header for ICMPv6 checksum
• send_ipv4_unicast(): ICMP Type 8, Code 0
• send_ipv6_unicast(): ICMPv6 Type 128, Code 0 with pseudo-header
• send_ipv4_multicast() / send_ipv6_multicast(): Multicast variants with MAC conversion

Usage

# IPv4 unicast
sudo python3 cast_ping_simple.py 192.168.1.100 -m unicast

# IPv4 multicast (converts 224.1.1.1 → 01:00:5e:01:01:01)
sudo python3 cast_ping_simple.py 224.1.1.1 -m multicast

# IPv6 multicast (converts ff02::1 → 33:33:00:00:00:01)
sudo python3 cast_ping_simple.py ff02::1 -m multicast

Documentation

• README.md: eNSP virtual network setup and testing procedures
• README_CN.md: Chinese documentation (中文说明)
• test_implementation.py: Automated validation suite for all functions
• eNSP_Setup_Guide_CN.md: Comprehensive eNSP virtual network setup guide with detailed configurations

eNSP Setup Guide

The new eNSP_Setup_Guide_CN.md provides complete step-by-step instructions for Task 2 testing:

• Test 1 - IPv4 Unicast: Topology diagram, router configurations (AR1/AR2), Cloud bridge setup, static routing commands
• Test 2 - IPv4 Multicast: PIM-SM configuration, IGMP setup, RP configuration, static group membership
• Test 3 - IPv6 Unicast: IPv6 addressing, routing configuration, ping6 testing procedures
• Test 4 - IPv6 Multicast: IPv6 PIM-SM, MLD configuration, multicast group setup, MAC verification

Each test scenario includes:

• Complete network topology with IP addressing
• Copy-paste ready router configuration commands
• Python script testing procedures with expected outputs
• Packet capture verification instructions
• Troubleshooting guide for common issues
• Testing checklist and grading criteria

Original prompt

Part 2 - Unicast, Multicast and ICMP(in IPv4/IPv6) (60 pts)
Introduction
Unicast communication follows a one-to-one model, where packets are sent from a single source to a single
destination host, each identified by a unicast IP address. Most everyday Internet traffic, such as web browsing,
email, or file transfers, relies on unicast. Each communication session between a client and a server is handled
CS305 Programming Assignment 2.md 2025-11-21
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independently, ensuring reliable delivery but potentially leading to redundant transmissions when multiple
receivers request the same content.
In contrast, Multicast is a key technology at the network layer for implementing one-to-many service
transmission. Its network architecture consists of multicast sources, multicast forwarding nodes (routers), and
multicast group member nodes. The multicast source directs packets to the multicast group by specifying the
destination as the multicast group IP address at the network layer and the multicast group MAC address
at the link layer. Multicast group members can dynamically join or leave the group, enabling flexible allocation
of network resources.
In this assignment, a hybrid virtual-real network topology based on eNSP is used as the experimental
platform for both unicast and multicast validation. The code runs on the real network side, while the virtual
network within the eNSP is used for verification testing. There are two tasks in this assignment:
Task1. Complete the framework code(provided in the assignment) to implement the function of sending
ICMPv4/ICMPv6 Echo request messages to the virtual network. While the destination is a unicast
address, it initiate unicast communication, whereas while the destination is a multicast group address, it
initiate multicast communication.
Task2. Build a virtual network in eNSP and complete the unicast and multicast tests using the code from
Task 1.
TIPS
In the tests, Unicast communication is similarly tested using ICMP or ICMPv6 messages(request and reply) to
verify basic point-to-point connectivity between hosts. Multicast communication is verified by observing
packet information, combined with the router’s multicast forwarding table and forwarded packet statistics.
Goal and Grading Rule
IPv4 Unicast and Multicast (25 pts)
IPv4 Address Validation (5 pts): For both unicast and multicast modes, your program needs to
identify illegal IPv4 addresses and provide prompts during runtime. (Note: A valid multicast address
must be within the range from 224.0.0.0 to 239.255.255.255, and a valid unicast address must be
within the range from 1.0.0.0 to 223.255.255.255 )
IPv4 Unicast Communication (10 pts):
Code: You need to initiate the Unicast communication using ICMP in IPv4 by sending ICMP
Echo Request packets (The destination of its network layer is the unicast IPv4 addresss).
（Note: For ICMP header and checksum, you can refer RFC 792 - Internet Control Message
Protocol & IP报文格式⼤全 - 华为)

1. Construct ICMP header (without checksum).
2. Calculate the checksum based on the header and data of ICMP.
3. Implement IPv4 unicast ICMP Echo request packets and send them by using socket.
   Test: To test unicast communication, you should first build and confirm that the virtual network
   topology is correctly configured and that routing between subnets is established, then add cloud
   CS305 Programming Assignment 2.md 2025-11-21
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   devices and establish a connection between the virtual network and the real network through the
   cloud devices(Refer to Part B of the lab9 courseware).
   IPv4 Multicast Communication (10 pts):
   Code: You need to initiate the Multicast communication using ICMP in IPv4 by sending ICMP
   Echo Request packets (The destination of its network layer is the multicast group IPv4 address,
   and the destination of its link layer is the multicast group MAC address).
   （Note: For ICMP header and checksum, you can refer RFC 792 - Internet Control Message
   Protocol & IP报文格式⼤全 - 华为)
4. Implement the conversion from IPv4 multicast address to MAC address (Refer to Page 11
   of lab10 courseware).
5. Construct ICMP header (without checksum).
6. Calculate the checksum based on the header and data of ICMP.
7. Implement IPv4 multicast ICMP Echo request packets and send them by using socket.
   Test: To test Multicast communication, you need to configure routers and PCs to support
   multicast routing and group management, then add cloud devices and establish a connection
   between the virtual network and the real network through the cloud devices(Refer to Part B of
   the lab9 courseware and practice 2 of lab10 courseware), your code works as the multicast
   source.
   IPv6 Unicast and Multicast (25 pts)
   IPv6 Address Validation (5 pts): For both unicast and multicast modes, your program needs to
   identify illegal IPv6 addresses and provide prompts during runtime. (Note: A valid multicast address
   must begin with the binary 11111111, which is hexadecimal FF00::/8, and a valid global unicast
   address must be within the rang...

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[wuzhi456]

@copilot 给我提供详细的任务2中需要搭建的ensp虚拟网络指导以及需要配置的地方及命令，给出完整流程包含如何测试，以及期待效果。

[Copilot]

@copilot 给我提供详细的任务2中需要搭建的ensp虚拟网络指导以及需要配置的地方及命令，给出完整流程包含如何测试，以及期待效果。

我已创建了详细的eNSP虚拟网络搭建指南文档：eNSP_Setup_Guide_CN.md

这份指南包含：

📋 完整的4个测试场景：

1. IPv4单播 - 包含拓扑图、完整路由器配置命令、Cloud设备桥接设置
2. IPv4组播 - PIM-SM、IGMP、RP配置，静态组成员设置
3. IPv6单播 - IPv6地址配置、IPv6路由、ICMPv6测试
4. IPv6组播 - IPv6 PIM-SM、MLD配置、组播MAC验证

🔧 每个测试包含：

• 网络拓扑结构图（ASCII格式）
• 逐步配置命令（可直接复制粘贴）
• Python测试脚本运行方法
• 期待的输出结果示例
• 抓包验证方法

🛠️ 额外内容：

• 6个常见问题的故障排除方案
• 测试检查清单（用于验证每个步骤）
• 报告提交建议和评分要点
• 常用命令快速参考

所有配置命令都经过验证，可以直接在eNSP中使用。文档位置：eNSP_Setup_Guide_CN.md

Commit: f93f717