diff --git a/boards/arm/cxd56xx/spresense/configs/rndis/defconfig b/boards/arm/cxd56xx/spresense/configs/rndis/defconfig
index a8f5b86df4..36a3ada066 100644
--- a/boards/arm/cxd56xx/spresense/configs/rndis/defconfig
+++ b/boards/arm/cxd56xx/spresense/configs/rndis/defconfig
@@ -38,6 +38,8 @@ CONFIG_ELF=y
 CONFIG_EXAMPLES_FTPC=y
 CONFIG_EXAMPLES_FTPD=y
 CONFIG_EXAMPLES_HELLO=m
+CONFIG_EXAMPLES_IPERF=y
+CONFIG_EXAMPLES_IPERFTEST_DEVNAME="eth0"
 CONFIG_EXAMPLES_TCPBLASTER=y
 CONFIG_EXAMPLES_TCPBLASTER_GROUPSIZE=500
 CONFIG_EXAMPLES_TCPBLASTER_SENDSIZE=1400
@@ -57,6 +59,7 @@ CONFIG_FTP_TMPDIR="/mnt/sd0"
 CONFIG_HAVE_CXX=y
 CONFIG_HAVE_CXXINITIALIZE=y
 CONFIG_I2C=y
+CONFIG_IOB_NBUFFERS=128
 CONFIG_LIBC_EXECFUNCS=y
 CONFIG_LIBM=y
 CONFIG_LIB_ENVPATH=y
diff --git a/boards/arm/cxd56xx/spresense/configs/rndis_smp/defconfig b/boards/arm/cxd56xx/spresense/configs/rndis_smp/defconfig
index 9c7b3c5cf4..ca48c5bb8f 100644
--- a/boards/arm/cxd56xx/spresense/configs/rndis_smp/defconfig
+++ b/boards/arm/cxd56xx/spresense/configs/rndis_smp/defconfig
@@ -41,6 +41,8 @@ CONFIG_ELF=y
 CONFIG_EXAMPLES_FTPC=y
 CONFIG_EXAMPLES_FTPD=y
 CONFIG_EXAMPLES_HELLO=m
+CONFIG_EXAMPLES_IPERF=y
+CONFIG_EXAMPLES_IPERFTEST_DEVNAME="eth0"
 CONFIG_EXAMPLES_TCPBLASTER=y
 CONFIG_EXAMPLES_TCPBLASTER_GROUPSIZE=500
 CONFIG_EXAMPLES_TCPBLASTER_SENDSIZE=1400
@@ -60,7 +62,7 @@ CONFIG_FTP_TMPDIR="/mnt/sd0"
 CONFIG_HAVE_CXX=y
 CONFIG_HAVE_CXXINITIALIZE=y
 CONFIG_I2C=y
-CONFIG_IOB_NBUFFERS=96
+CONFIG_IOB_NBUFFERS=128
 CONFIG_LIBC_EXECFUNCS=y
 CONFIG_LIBM=y
 CONFIG_LIB_ENVPATH=y