Network

Routing

Path selection

Ref: Routing Path Selection

Priority

1. Prefix-Length

   Longer subnet masks are preferred

2. Metric

   Lower metric/cost is preferred

Layer

Internet Standard	OSI Model	Internet Protocol Suite
Application	Application Presentation Session	BGP, DHCP, DNS, FTP, HTTP, HTTPS, IMAP, SMTP, LDAP, NTP
Transport	Transport	TCP, UDP, SCTP
Internet	Network	IPv4, IPv6, IPsec, ICMP, ICMPv6, IGMP, OSPF
Link	Data Link	ARP, NDP
	Physical	IEEE 802.11 (WiFi), 100BASE-TX, 1000BASE-T

OSI: Open Systems Interconnection

Internet Standard: RFC1122

IGP (Interior Gateway Protocol)

內部閘道協定

• Within an autonomous system

Include

• RIP
• IGRP
• OSPF
• IS-IS

CPE

Customer Premises Equipment

用戶端設備

• 位於 User 端
• 用於 User 與 ISP 連接的裝置
• 例如 ISP 的 Router，電話…