๐Ÿ“ฆ MTU ๊ฒฝ๋กœ ๊ฒ€์ƒ‰ ๋ฐ ๋‹จํŽธํ™” ๋ถ„์„๊ธฐ

์บก์Аํ™” ์˜ค๋ฒ„ํ—ค๋“œ ํ›„ ์œ ํšจ MTU ๊ณ„์‚ฐ, ๋‹จํŽธํ™” ์‹œ๊ฐํ™” ๋ฐ PMTUD ๋ฌธ์ œ ํ•ด๊ฒฐ

๐Ÿ—๏ธ ์บก์Аํ™” ์Šคํƒ (์žฌ์ •๋ ฌํ•˜๋ ค๋ฉด ๋“œ๋ž˜๊ทธ)

์บก์Аํ™” ๋ ˆ์ด์–ด๊ฐ€ ์ถ”๊ฐ€๋˜์ง€ ์•Š์•˜์Šต๋‹ˆ๋‹ค. ๋ ˆ์ด์–ด๋ฅผ ์ถ”๊ฐ€ํ•˜์—ฌ MTU์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ํ™•์ธํ•˜์„ธ์š”.
์œ ํšจ ํŽ˜์ด๋กœ๋“œ MTU
1500
๋ฐ์ดํ„ฐ์— ์‚ฌ์šฉ ๊ฐ€๋Šฅํ•œ ๋ฐ”์ดํŠธ
์ €์žฅ๋˜์ง€ ์•Š์Œ
๐Ÿ“– ์‚ฌ์šฉ ๋ฐฉ๋ฒ• โ–ผ
  • ๋น ๋ฅธ ์‹œ์ž‘: ํ”„๋ฆฌ์…‹ ๋ฒ„ํŠผ(Internet, PPPoE, Azure ๋“ฑ)์„ ํด๋ฆญํ•˜์—ฌ ์ผ๋ฐ˜์ ์ธ ์‹œ๋‚˜๋ฆฌ์˜ค๋ฅผ ๋กœ๋“œํ•˜์„ธ์š”.
  • ์‚ฌ์šฉ์ž ์ง€์ • ๊ณ„์‚ฐ: ๊ธฐ๋ณธ MTU๋ฅผ ์„ค์ •ํ•˜๊ณ  ์บก์Аํ™” ๋ ˆ์ด์–ด๋ฅผ ํ•˜๋‚˜์”ฉ ์ถ”๊ฐ€ํ•˜์„ธ์š”.
  • ๊ฒฐ๊ณผ: ์œ ํšจ ํŽ˜์ด๋กœ๋“œ MTU, ๊ถŒ์žฅ TCP MSS ๋ฐ ์˜ค๋ฒ„ํ—ค๋“œ ๋ถ„์„์„ ํ™•์ธํ•˜์„ธ์š”.
  • ๋‹จํŽธํ™”: MTU๊ฐ€ 1500 ๋ฏธ๋งŒ์ธ ๊ฒฝ์šฐ, ์‹œ๊ฐ์  ๋‹จํŽธํ™” ๋‹ค์ด์–ด๊ทธ๋žจ์ด ์ž๋™์œผ๋กœ ํ‘œ์‹œ๋ฉ๋‹ˆ๋‹ค.
  • ๋ฌธ์ œ ํ•ด๊ฒฐ: PMTUD ์ˆœ์„œ๋„๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ๊ฒฝ๋กœ MTU ๊ฒ€์ƒ‰ ๋ฌธ์ œ๋ฅผ ์ง„๋‹จํ•˜์„ธ์š”.
  • ์„ฑ๋Šฅ ์˜ํ–ฅ: ๋Œ€์—ญํญ ๋‚ญ๋น„ ๊ณ„์‚ฐ๊ธฐ๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ๋‹จํŽธํ™”์˜ ์‹ค์ œ ๋น„์šฉ์„ ํ™•์ธํ•˜์„ธ์š”.

MTU ๊ณ„์‚ฐ ๊ฒฐ๊ณผ

์œ ํšจ ํŽ˜์ด๋กœ๋“œ MTU
1500
๋ฐ์ดํ„ฐ์— ์‚ฌ์šฉ ๊ฐ€๋Šฅํ•œ ๋ฐ”์ดํŠธ
์ด ์˜ค๋ฒ„ํ—ค๋“œ
0
์†Œ๋น„๋œ ๋ฐ”์ดํŠธ
๊ถŒ์žฅ TCP MSS
1460
MTU - 40 (IP+TCP ํ—ค๋”)
๊ธฐ๋ณธ MTU: 1500 bytes
์บก์Аํ™” ์˜ค๋ฒ„ํ—ค๋“œ: 0 bytes
์œ ํšจ MTU: 1500 bytes
IP + TCP ํ—ค๋”: 40 bytes (20 IP + 20 TCP)
์ตœ๋Œ€ TCP ํŽ˜์ด๋กœ๋“œ: 1460 bytes
ํšจ์œจ์„ฑ: 97.3%

๐Ÿ’ธ ๋Œ€์—ญํญ ๋‚ญ๋น„ ๊ณ„์‚ฐ๊ธฐ

โ„น๏ธ ์„ฑ๋Šฅ ์˜ํ–ฅ: ๋„คํŠธ์›Œํฌ ๋Œ€์—ญํญ์—์„œ ๋‹จํŽธํ™”๊ฐ€ ์ฐจ์ง€ํ•˜๋Š” ์‹ค์ œ ๋น„์šฉ์„ ๊ณ„์‚ฐํ•ฉ๋‹ˆ๋‹ค.

๐Ÿ” ๊ฒฝ๋กœ MTU ๊ฒ€์ƒ‰ (PMTUD) ๋Œ€ํ™”ํ˜• ๋ฌธ์ œ ํ•ด๊ฒฐ์‚ฌ

โ„น๏ธ ๋Œ€ํ™”ํ˜• ์ˆœ์„œ๋„: ์•„๋ž˜ ์ง„๋‹จ ๋‹จ๊ณ„๋ฅผ ์ˆœ์„œ๋Œ€๋กœ ํด๋ฆญํ•˜์—ฌ PMTUD ๋ฌธ์ œ๋ฅผ ํ•ด๊ฒฐํ•˜์„ธ์š”.
๐Ÿš€ ์‹œ์ž‘: ํŒจํ‚ท ์†์‹ค์ด๋‚˜ ๋А๋ฆฐ ์„ฑ๋Šฅ ๋ฌธ์ œ๊ฐ€ ์žˆ์Šต๋‹ˆ๊นŒ?
์ง„๋‹จ ํ”„๋กœ์„ธ์Šค๋ฅผ ์‹œ์ž‘ํ•˜๋ ค๋ฉด ํด๋ฆญํ•˜์„ธ์š”. ์ฒด๊ณ„์ ์ธ ๋ฌธ์ œ ํ•ด๊ฒฐ ๋‹จ๊ณ„๋ฅผ ์•ˆ๋‚ดํ•ด ๋“œ๋ฆฌ๊ฒ ์Šต๋‹ˆ๋‹ค.

๐Ÿ”ง ๊ตฌ์„ฑ ์˜ˆ์‹œ

โ„น๏ธ TCP MSS ํด๋žจํ•‘: ๋‹จํŽธํ™”๋ฅผ ๋ฐฉ์ง€ํ•˜๋ ค๋ฉด ๋ผ์šฐํ„ฐ์— ์ด ์„ค์ •์„ ๊ตฌ์„ฑํ•˜์„ธ์š”.
! Cisco IOS/IOS-XE
interface GigabitEthernet0/0
ip tcp adjust-mss 1460
! Juniper JunOS
set interfaces ge-0/0/0 unit 0 family inet mtu 1500
set interfaces ge-0/0/0 unit 0 family inet tcp-mss 1460
# Linux iptables
iptables -t mangle -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss 1460

๐Ÿš€ ์ ๋ณด ํ”„๋ ˆ์ž„ ๋ถ„์„

โ„น๏ธ ์ ๋ณด ํ”„๋ ˆ์ž„: ๋” ํฐ MTU ํฌ๊ธฐ๋Š” ์Šคํ† ๋ฆฌ์ง€ ๋ฐ ๋ฐ์ดํ„ฐ์„ผํ„ฐ ๋„คํŠธ์›Œํฌ์˜ ์ฒ˜๋ฆฌ๋Ÿ‰์„ ํ–ฅ์ƒ์‹œํ‚ต๋‹ˆ๋‹ค.
ํ‘œ์ค€ ํ”„๋ ˆ์ž„ ํšจ์œจ์„ฑ: 97.3% (1460/1500)
์ ๋ณด ํ”„๋ ˆ์ž„ (9000 MTU): 99.6% ํšจ์œจ์„ฑ (8960/9000)
GB๋‹น ํ”„๋ ˆ์ž„ ์ˆ˜ (ํ˜„์žฌ): ~731,000 ํ”„๋ ˆ์ž„
GB๋‹น ํ”„๋ ˆ์ž„ ์ˆ˜ (์ ๋ณด 9000): ~119,000 ํ”„๋ ˆ์ž„ (84% ๊ฐ์†Œ)
CPU ์ ˆ๊ฐ (์ ๋ณด ๋Œ€ ํ‘œ์ค€): ~84% ์ธํ„ฐ๋ŸฝํŠธ ๊ฐ์†Œ

๊ถŒ์žฅ ์‚ฌํ•ญ:

  • ํ‘œ์ค€ 1500 MTU: ์ธํ„ฐ๋„ท, ์ผ๋ฐ˜ ์บ ํผ์Šค ๋„คํŠธ์›Œํฌ, ํ˜ผํ•ฉ ํ™˜๊ฒฝ
  • ๋ฒ ์ด๋น„ ์ ๋ณด (2000): ๋ฉ”ํŠธ๋กœ ์ด๋”๋„ท, ์ผ๋ถ€ MPLS ๋„คํŠธ์›Œํฌ
  • ์ ๋ณด ํ”„๋ ˆ์ž„ (9000): iSCSI, NFS, ์„œ๋ฒ„ ๊ฐ„ ํ†ต์‹ , ๋ฐ์ดํ„ฐ์„ผํ„ฐ ํŒจ๋ธŒ๋ฆญ
  • ์Šˆํผ ์ ๋ณด (9216): ์Šคํ† ๋ฆฌ์ง€ ๋„คํŠธ์›Œํฌ, 10GbE+ ๋ฐ์ดํ„ฐ์„ผํ„ฐ