Lecture 210: Routing Policy - IP-based
- 课程：[NEW] AWS Certified Advanced Networking Specialty 2026
- 视频时长：01:45
- 来源：Udemy Lecture 37045740
- Slide 数量：3
- 画面切换：00:41、01:14
扫描说明
逐条读取了 Udemy 页面中的 43 条英文 Transcript cue，并按时间轴扫描全长约 01:45 的视频。依据 IP-based 核心机制、CIDR Collection 与 Record Mapping、两类 Client 的解析结果划分为 3 个小节。截图均在 Transcript 侧栏关闭、播放器控件隐藏后复核，统一为 1364×770。
Transcript 来自 Udemy 页面自带的英文自动字幕，没有使用 ASR。下面保留页面原文，包括其中的语法或识别错误。
1. IP-based Routing 按 Client IP 所属 CIDR 选择 Endpoint
时间范围：00:00–00:41
总结 / Summary
中文
IP-based Routing 由用户提供 Client CIDR List，并把每个 IP Range 映射到对应 Location/Endpoint。Route 53 根据发起 DNS Query 的 Client IP 匹配 CIDR，而不是按地理位置推断或测量 Latency。已知 ISP、企业出口或 Partner Network 的地址范围时，可用它优化 Performance 或降低 Network Cost。
English
IP-based routing uses a client CIDR list supplied by the user and maps each IP range to a location or endpoint. Route 53 matches the client IP behind the DNS query to a CIDR rather than inferring geography or measuring latency. When ISP, enterprise-egress, or partner-network ranges are known, this can optimize performance or reduce network cost.
Transcript
00:00 So now let's talk
00:01 about another routing policy
00:02 called the IP-based Routing
00:04 which is very intuitive to think about
00:06 because you're going to define the routing based
00:08 on the client IP addresses.
00:10 In Route 53, you're going to define a list of CIDRs,
00:13 they are IP ranges for your clients,
00:15 and you're going to say, based on the CIDR
00:18 which location the traffic should be sent to.
00:21 So the use cases will be to optimize performance
00:23 because you know the IP ahead of time
00:25 or to reduce network costs
00:26 because you know where the IPs are coming from.
00:29 So an example is that if you know
00:31 that you have a specific internet provider
00:33 and they are using a specific CIDR of IP addresses
00:37 you can route them
00:38 to a specific endpoint thanks to this strategy.
2. CIDR Collection 定义 Location，再由同名 Record 关联各 Location
时间范围：00:41–01:14
总结 / Summary
中文
示例 CIDR Collection 定义 location-1 = 203.0.113.0/24、location-2 = 200.5.4.0/24。随后为 example.com 建立两条 IP-based Record：location-1 的 Value 为 1.2.3.4，location-2 的 Value 为 5.6.7.8，对应两台 EC2 Public IP。Location 名把 CIDR 集合与 DNS Answer 连接起来。
English
The example CIDR collection defines location-1 as 203.0.113.0/24 and location-2 as 200.5.4.0/24. Two IP-based records for example.com map location-1 to value 1.2.3.4 and location-2 to 5.6.7.8, representing two EC2 public addresses. Location names connect the CIDR collection to DNS answers.
Transcript
00:41 So let's go for an example.
00:42 In Route 53, I'm going to define two locations
00:46 with two different CIDR blocks.
00:47 As you can see, one start with 203
00:49 and the other one start with 200 and the defined IP ranges.
00:54 Now we are going to link these locations
00:56 to a specific record.
00:57 So for example.com we're going to have location one.
01:00 So the first CIDR block to send
01:03 to the value 1.2.3.4,
01:05 and the second location, the CIDR block number two,
01:08 to send it to 5.6.7.8.
01:10 And these represents the public IP of two EC2 instances.
3. User A/B 分别命中自己的 CIDR，得到不同 EC2 Answer
时间范围：01:14–01:45
总结 / Summary
中文
User A 的 IP 203.0.113.56 属于 203.0.113.0/24，因此 Route 53 返回 location-1 的 1.2.3.4；User B 的 200.5.4.100 属于 200.5.4.0/24，因此返回 location-2 的 5.6.7.8。它实现可预测的 Source-IP-to-Endpoint Mapping，不是随机、权重或最近 Region 选择。
English
User A at 203.0.113.56 belongs to 203.0.113.0/24, so Route 53 returns location-1 value 1.2.3.4. User B at 200.5.4.100 belongs to 200.5.4.0/24 and receives location-2 value 5.6.7.8. This is deterministic source-IP-to-endpoint mapping, not randomness, weighting, or nearest-region selection.
Transcript
01:14 Now, as you would expect, if a user comes in
01:16 with a specific IP that is part
01:19 of the location one CIDR block, they will be directed
01:22 to the first EC2 instance of IP 1.2.3.4,
01:26 and the user B, with a second IP address
01:29 that belongs to the location two,
01:31 will be redirected and will have a DNS query response
01:35 to the EC2 instance of IP 5.6.7.8.
01:39 And that's it for IP based routing.
01:41 It's very simple and I hope you liked it.
01:43 I will see you in the next lecture.
整讲总结 / Overall Summary
中文
IP-based Routing 把已知 Client CIDR Collection 映射到 Location，再让同名 DNS Record 为每个 Location 返回指定 Endpoint。它适合按 ISP/企业地址范围进行确定性分流，以优化性能或成本；判断依据是 Client IP CIDR，而非 Geography、Latency 或 Weight。
English
IP-based routing maps known client CIDR collections to locations and returns a designated endpoint through same-name DNS records for each location. It enables deterministic distribution by ISP or enterprise address ranges for performance or cost goals, using client-IP CIDR rather than geography, latency, or weight.
返回顶部 ↑