Question on network policy for lab 6.1
Hello,
In the last part of lab 6.1 we create a networkpolicy to only allow Ingress from Cidr 192.168.0.0/16 on port TCP 80.
This is confirmed working because from the second node (IP 10.132.0.4), I can no longer curl the node's internal IP (10.132.0.3:32000), nor the external IP from the master node from my laptop. And it still works to curl the pod's IP 192.168.174.82 on port 80 from the second and master node.
However what I don't understand is that I can still curl the master node's internal IP when I'm on the master node itself (10.132.0.3). This does not work like I said from the second node. If I remove the network policy it again also works from the second node.
Also in the logs of the webserver container of the pod, I can see incoming connection from 10.132.0.3. I don't understand how this is possible since CIDR ingress is limited to 192.168.0.0/16. I first thought the master node would use another NIC because it also has IP 192.168.174.64 from the tunl0 interface, but then my logs still show successful connection from 10.132.0.3. If this was true, my second node, with tunl0 interface having ip 192.168.247.2 should also be able to get in.
What am I missing here? This is my 'allclosed.yaml':
apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: deny-default spec: podSelector: {} policyTypes: - Ingress ingress: - from: - ipBlock: cidr: 192.168.0.0/16 ports: - port: 80 protocol: TCP # - Egress
Comments
-
Hello,
It seems like with the NetworkPolicy in place you can still connect locally, but not from a remote system. Without tracing the traffic in detail this would indicate that the local connection is not being ingested in the same manner and thus bypassing the policy, in a similar manner that using the loopback interface does not actually use a full NIC, and remains in the node itself.
If you have two windows up are you seeing the incoming connection at the same time as you curl from an exterior instance? I'm wondering if you are seeing previous attempts, not ones where the policy was in place. I would agree that with the policy in place there should be no request to the container. If you indeed see traffic immediately , and the policy is in place please let me know and I will try to investigate further.
Regards,
0 -
hi,
thanks for getting back. I have 2 connections to my node1, one doing a $watch on the logs, and the other doing the curl. When I do the new curl, I do see the new log in the other window. Is this what you are referring to?
0 -
Hello,
Yes. You should see traffic in the log window. This can be useful for troubleshooting issues and to see activity as the requests come in.
Regards,
0
Categories
- All Categories
- 208 LFX Mentorship
- 208 LFX Mentorship: Linux Kernel
- 738 Linux Foundation IT Professional Programs
- 340 Cloud Engineer IT Professional Program
- 167 Advanced Cloud Engineer IT Professional Program
- 67 DevOps Engineer IT Professional Program
- 133 Cloud Native Developer IT Professional Program
- 123 Express Training Courses
- 123 Express Courses - Discussion Forum
- 6K Training Courses
- 40 LFC110 Class Forum - Discontinued
- 67 LFC131 Class Forum
- 40 LFD102 Class Forum
- 223 LFD103 Class Forum
- 18 LFD110 Class Forum
- 35 LFD121 Class Forum
- 18 LFD133 Class Forum
- 7 LFD134 Class Forum
- 18 LFD137 Class Forum
- 71 LFD201 Class Forum
- 4 LFD210 Class Forum
- 3 LFD210-CN Class Forum
- 2 LFD213 Class Forum - Discontinued
- 128 LFD232 Class Forum - Discontinued
- 2 LFD233 Class Forum
- 4 LFD237 Class Forum
- 24 LFD254 Class Forum
- 691 LFD259 Class Forum
- 111 LFD272 Class Forum
- 4 LFD272-JP クラス フォーラム
- 11 LFD273 Class Forum
- 118 LFS101 Class Forum
- 1 LFS111 Class Forum
- 3 LFS112 Class Forum
- 2 LFS116 Class Forum
- 4 LFS118 Class Forum
- 4 LFS142 Class Forum
- 5 LFS144 Class Forum
- 4 LFS145 Class Forum
- 2 LFS146 Class Forum
- 3 LFS147 Class Forum
- 9 LFS151 Class Forum
- 2 LFS157 Class Forum
- 19 LFS158 Class Forum
- 6 LFS162 Class Forum
- 2 LFS166 Class Forum
- 4 LFS167 Class Forum
- 2 LFS170 Class Forum
- 2 LFS171 Class Forum
- 3 LFS178 Class Forum
- 3 LFS180 Class Forum
- 2 LFS182 Class Forum
- 5 LFS183 Class Forum
- 31 LFS200 Class Forum
- 737 LFS201 Class Forum - Discontinued
- 3 LFS201-JP クラス フォーラム
- 18 LFS203 Class Forum
- 120 LFS207 Class Forum
- 2 LFS207-DE-Klassenforum
- 1 LFS207-JP クラス フォーラム
- 302 LFS211 Class Forum
- 56 LFS216 Class Forum
- 51 LFS241 Class Forum
- 46 LFS242 Class Forum
- 38 LFS243 Class Forum
- 14 LFS244 Class Forum
- 2 LFS245 Class Forum
- 46 LFS250 Class Forum
- 2 LFS250-JP クラス フォーラム
- 1 LFS251 Class Forum
- 148 LFS253 Class Forum
- 1 LFS254 Class Forum
- 1 LFS255 Class Forum
- 7 LFS256 Class Forum
- 1 LFS257 Class Forum
- 1.2K LFS258 Class Forum
- 10 LFS258-JP クラス フォーラム
- 117 LFS260 Class Forum
- 158 LFS261 Class Forum
- 42 LFS262 Class Forum
- 82 LFS263 Class Forum - Discontinued
- 15 LFS264 Class Forum - Discontinued
- 11 LFS266 Class Forum - Discontinued
- 24 LFS267 Class Forum
- 19 LFS268 Class Forum
- 30 LFS269 Class Forum
- 201 LFS272 Class Forum
- 2 LFS272-JP クラス フォーラム
- 1 LFS274 Class Forum
- 4 LFS281 Class Forum
- 9 LFW111 Class Forum
- 258 LFW211 Class Forum
- 181 LFW212 Class Forum
- 13 SKF100 Class Forum
- 1 SKF200 Class Forum
- 1 SKF201 Class Forum
- 791 Hardware
- 199 Drivers
- 68 I/O Devices
- 37 Monitors
- 98 Multimedia
- 174 Networking
- 91 Printers & Scanners
- 85 Storage
- 755 Linux Distributions
- 82 Debian
- 67 Fedora
- 16 Linux Mint
- 13 Mageia
- 23 openSUSE
- 147 Red Hat Enterprise
- 31 Slackware
- 13 SUSE Enterprise
- 352 Ubuntu
- 465 Linux System Administration
- 39 Cloud Computing
- 71 Command Line/Scripting
- Github systems admin projects
- 91 Linux Security
- 78 Network Management
- 101 System Management
- 47 Web Management
- 56 Mobile Computing
- 17 Android
- 28 Development
- 1.2K New to Linux
- 1K Getting Started with Linux
- 366 Off Topic
- 114 Introductions
- 171 Small Talk
- 20 Study Material
- 534 Programming and Development
- 293 Kernel Development
- 223 Software Development
- 1.2K Software
- 212 Applications
- 182 Command Line
- 3 Compiling/Installing
- 405 Games
- 312 Installation
- 79 All In Program
- 79 All In Forum
Upcoming Training
-
August 20, 2018
Kubernetes Administration (LFS458)
-
August 20, 2018
Linux System Administration (LFS301)
-
August 27, 2018
Open Source Virtualization (LFS462)
-
August 27, 2018
Linux Kernel Debugging and Security (LFD440)