@echo off
Setlocal Enabledelayedexpansion
for /f "tokens=1,2,*" %%i in ('more +13^<%~fs0') do (
  set var=%%i
  if "!var:~,2!"=="dn" (
    set str=%%i
  ) else (
    if "!var:~,5!"=="lantx" (
      echo !str! %%k
    )
  )
)
pause&goto :eof
dn:1
----------------------------
name:y
type:6x17  port:36
lantx:3  host 3 1 1 3
----------------------------
dn:2
----------------------------
name:undef
type:undef
----------------------------
dn:3
----------------------------
name:y
tyep:6x17    port:29
lantx:3    host 3 2 1 4
-----------------------------

@echo off
setlocal enabledelayedexpansion
(
  for /f "eol=- tokens=1,2,* delims=t" %%a in (1.txt) do (
    if "%%a" lss "e" (
      set dn=%%a
    ) else (
      if "%%a" lss "m" echo !dn!%%c
    )
  )
)>2.txt

@echo off
type nul>2.txt
Setlocal Enabledelayedexpansion
for /f "tokens=1,2,*" %%i in ('type 1.txt') do (
  set var=%%i
  if "!var:~,2!"=="dn" (
    set str=%%i
  ) else (
    if "!var:~,5!"=="lantx" (
      echo !str! %%k
    )
  )
)>>2.txt
start 2.txt