The tg3 module is absent in the libre kernel due to certain models requiring proprietary blobs, so in distros like Parabola it is not working without recompiling the kernel. See https://h-node.org/ethernetcards/view/en/415/Broadcom-Corporation-NetXtreme-BCM5782-Gigabit-Ethernet/2/1/Broadcom-Corporation/undef/undef/undef/ethernet-works/undef for more info

lspci -vmmnn

Slot:	09:00.0
Class:	Ethernet controller [0200]
Vendor:	Broadcom Corporation [14e4]
Device:	NetXtreme BCM5755M Gigabit Ethernet PCI Express [1673]
SVendor:	Dell [1028]
SDevice:	Device [01f9]
Rev:	02

lspci -nnk

09:00.0 Ethernet controller [0200]: Broadcom Corporation NetXtreme BCM5755M Gigabit Ethernet PCI Express [14e4:1673] (rev 02)
	Subsystem: Dell Device [1028:01f9]
	Kernel driver in use: tg3
	Kernel modules: tg3

lspci -vvnnk

09:00.0 Ethernet controller [0200]: Broadcom Inc. and subsidiaries NetXtreme BCM5755M Gigabit Ethernet PCI Express [14e4:1673] (rev 02)
	Subsystem: Dell NetXtreme BCM5755M Gigabit Ethernet PCI Express [1028:01f9]
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Latency: 0, Cache Line Size: 64 bytes
	Interrupt: pin A routed to IRQ 10
	Region 0: Memory at fe7f0000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: [48] Power Management version 3
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot+,D3cold+)
		Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=1 PME-
	Capabilities: [50] Vital Product Data
		Product Name: Broadcom NetXtreme Gigabit Ethernet Controller
		Read-only fields:
			[PN] Part number: BCM95755m
			[EC] Engineering changes: 01f9.004
			[SN] Serial number: 0123456789
			[MN] Manufacture ID: 14e4
			[RV] Reserved: checksum good, 28 byte(s) reserved
		Read/write fields:
			[YA] Asset tag: XYZ01234567
			[RW] Read-write area: 107 byte(s) free
		End
	Capabilities: [58] Vendor Specific Information: Len=78 <?>
	Capabilities: [e8] MSI: Enable- Count=1/1 Maskable- 64bit+
		Address: 50236c306080bf94  Data: bf36
	Capabilities: [d0] Express (v1) Endpoint, MSI 00
		DevCap:	MaxPayload 128 bytes, PhantFunc 0, Latency L0s <4us, L1 unlimited
			ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset- SlotPowerLimit 6.500W
		DevCtl:	CorrErr- NonFatalErr- FatalErr- UnsupReq-
			RlxdOrd- ExtTag+ PhantFunc- AuxPwr- NoSnoop-
			MaxPayload 128 bytes, MaxReadReq 512 bytes
		DevSta:	CorrErr- NonFatalErr- FatalErr- UnsupReq- AuxPwr+ TransPend-
		LnkCap:	Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Exit Latency L0s <4us, L1 <64us
			ClockPM+ Surprise- LLActRep- BwNot- ASPMOptComp-
		LnkCtl:	ASPM L0s Enabled; RCB 64 bytes Disabled- CommClk+
			ExtSynch- ClockPM+ AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 2.5GT/s (ok), Width x1 (ok)
			TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
	Capabilities: [100 v1] Advanced Error Reporting
		UESta:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
		UEMsk:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
		UESvrt:	DLP+ SDES- TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol-
		CESta:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr-
		CEMsk:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr+
		AERCap:	First Error Pointer: 00, ECRCGenCap+ ECRCGenEn- ECRCChkCap+ ECRCChkEn-
			MultHdrRecCap- MultHdrRecEn- TLPPfxPres- HdrLogCap-
		HeaderLog: 00000000 00000000 00000000 00000000
	Capabilities: [13c v1] Virtual Channel
		Caps:	LPEVC=0 RefClk=100ns PATEntryBits=1
		Arb:	Fixed- WRR32- WRR64- WRR128-
		Ctrl:	ArbSelect=Fixed
		Status:	InProgress-
		VC0:	Caps:	PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
			Arb:	Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256-
			Ctrl:	Enable+ ID=0 ArbSelect=Fixed TC/VC=01
			Status:	NegoPending- InProgress-
	Capabilities: [160 v1] Device Serial Number 00-1c-23-ff-fe-1e-18-00
	Capabilities: [16c v1] Power Budgeting <?>