GitHub/school-of-sre
1
0
Fork 0
mirror of https://github.com/linkedin/school-of-sre synced 2026-01-21 07:58:03 +00:00
Code Issues Packages Projects Releases Wiki Activity

Fixed images

Browse Source
This commit is contained in:
Nishant Singh
2020-11-12 10:53:51 +05:30
parent 7f91761241
commit 5192962be8
14 changed files with 48 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
courses/security/network_security.md
View File

@@ -142,7 +142,10 @@ Let us see how we keep a check on the perimeter i.e the edges, the first layer o
- Nmap is often used to determine alive hosts in a network, open ports on those hosts, services running on those open ports, and version identification of that service on that port.
- More at http://scanme.nmap.org/
![image16](images/image16.png)
```
nmap [scan type] [options] [target specification]
```
Nmap uses 6 different port states:
@@ -413,8 +416,17 @@ TCP Flags
![image20](images/image20.png)
- Abuse of the normal operation or settings of these flags can be used by attackers to launch DoS attacks. This causes network servers or web servers to crash or hang.
![image21](images/image21.png)
- The attacker's ultimate goal is to write special programs or pieces of code that are able to construct these illegal combinations resulting in an efficient DoS attack.
```
| SYN | FIN | PSH | RST | Validity|
|------|------|-------|------|---------|
| 1 |1 |0 |0 |Illegal Combination
| 1 |1 |1 |0 |Illegal Combination
| 1 |1 |0 |1 |Illegal Combination
| 1 |1 |1 |1 |Illegal Combination
```
- The attacker's ultimate goal is to write special programs or pieces of code that are able to construct these illegal combinations resulting in an efficient DoS attack.
SYN FLOOD